This update for liferea fixes the following issues:

- Fix missing python3-gobject-Gdk runtime dependency (boo#1187936)

liferea was updated to version 1.13.6:

* Change reader mode toggle from item view icon to toggle entry in item view context menu.
* #343: UX redesign of the update message in the status bar. Now shows a update counter of the feeds being in update.
* #964: Added pane position fix plugin providing a workaround for pane position issues when using the headerbar
* #983: Use GtkFileChooserNative to allow selecting local files when run in sandbox.
* Fixes #780: Improve date formatting when in locale en_GB
* Fixes #944: Broken RTL text direction in feed content view
* Fixes #949: Regression in notification plugin that caused it to show non-new items 
* Fixes #963: Checking for git command in plugin installer -> warn user
* Fixes #973: Broken CSS in Webkit2Gtk >= 2.32
* Updated Albanian translation
* Updated French translation
* Updated Italian translation
* Updated German translation
* #907: Add new search folder property that allows hiding read items
* Now always shows the unread count of a search folder (instead of the item count) in the feed list
* Now search folders are automatically rebuild when rules are changed
* Adds a new simple focus plugin that adds transparency on the feed list when it is not focussed.
* Add F10 hotkey to headerbar plugin to allow triggering the hamburger menu
* Update Flatpak AppData with release dates
* Make several plugins support gettext
* Fixes #192: wrong button order of media player in RTL locales
* Fixes #343: Usability of update infos in status bar. Now a total count is displayed on mass-updates and a per-feed info on single feed updates
* Fixes #809: Usability of feed fetching errors.
* Updated Polish translation
* Updated German translation
* Prevent endless loop on favicon discovery
* #903: Prevent endless loop in feed autodiscovery
* #912: Allow mutiple feed in same libnotify notification
* Further favicon discovery improvements: now detects all types of Apple Touch Icons, MS Tile Images and Safari Mask Icons Fixes #440
* Add reader mode toggle in the item view
* #876 Add reader mode preference
* Implement support for subscribing to LD+Json metadata listings e.g. concert or theater event listings
* Provide the default icon for feeds with no favicon as SVG for nicer rendering in wide view. Drop some unused icons. Replace tray icon with scalable version.
* Fixes CRITICAL on trayicon plugin init
* Fixes #884: Content of wrong feed is shown
* Fixes #900: Flatpak needs icon named after appid
* Fixes #908, #332: Search folder are not case-insensitive as documented
* Fixes #899: Truncated articles (on 'Extrat full content')
* #902: Updated Polish translation
* #893: Update of bookmarking sites
* #888: Changes required for Flathub
* #882: Implement support for Webkits Intelligent Tracking Protection
* #875: Add <Ctrl>-0 hotkey to reset zoom
* #874: Add debug printing of SAX parser errors
* #846: Remove deprecated usage of gdk_screen_*
* #844: Update metainfo path (appdata target directory)
* #776: CSS color update on theme change without restart
* Fixes #883: Feed with comments: last comment replaces all content
* Fixes #866: Bad encoding in doc/html/reference_de.html
* Fixes #865: Fixes view mode switch
* Fixes #841: Now shows progress bar when loading websites
* Fixes #828: Crashing with segfault after opening feed articles
* Fixes XLST exception on mediarss feeds with description
* Drop blogChannel namespace support
* Support multi-feed discovery
* Default to https:// instead of http:// when user doesn't provide protocol on subscribing feed
* Drop CDF channel legacy support
* Drop Atom 0.2/0.3 (aka Pie) legacy support
* #893: Added Persion default feed list
* #890: Update of Indionesian translation
* #890: Update of French translation
* #846, #864, #735: Fix main menu/toolbar not being translated
* #854: Adding new search folder options to match subscription source ULR and parent folder name.
* #851: Add accessibility check to code tests
* #851: Fix accessibility annotations for several combo boxes.
* #850: Fix embedded youtube video bug.
* #765: Embed YouTube videos from MediaRSS feeds
* #749: Add Readability.js library (Apache 2.0 licensed) and auto-apply Readability.js to all headlines
* Drop unused glade/google_source.ui
* Drop support of combined view mode, this is necessary to add rich content support which relies on DOM transformation and Readability.js
* Drop ns_photo support, as it is rarely used and allows us to get rid of XSLT extra handling
* #747: Font improvements
* #250 Update some dialog labels
* #803: Fix legacy links to mailing list and IRC in documentation.
* Updated German translation
* #861: Updated Spanish translation
* Fixes #840: OPML source subfolders not working
* #837: Removing GTimeVal references
* #827: Respect global update refresh interval for TheOldReader
* #826: Fix save/restore position issues with tray icon
* #822: Improve performance of item list loading
* Fixes #821: Skip current item when finding next unread item
* #815: Add support for subscribing to HTML5 websites without RSS/Atom feeds by extracting article titles,links and descriptions
* #816: Increase size of stored favicons to 128x128px to improve icon quality in 3-pane wide view. Also add favicon URL discovery tests.
* Fixes #821: Skip current selected unread item on 'next unread item'
* #800: Expose remove-item action for plugins
* Fixes #799: plugins/headerbar.py translations not active
* Fixes #783: Update IS_STATE when update item in itemlistview
* #752: Trayicon plugin has now a configuration option to change the behaviour when closing Liferea.
* Fixes #693: Add trayicon plugin option to disable minimizing to tray
* #764: Add MediaRSS support (e.g. Youtube feeds) to display descriptions and thumbnails
* #773: Add WebKit Inspector menu option to HTML view when run with --debug-html (by sillyslux)
* #714: Replaces deprecated gtk_menu_popup
* #705: New hotkey Ctrl-O to open enclosures
* #680: Add xdg-email command to item list popup menu
* Drop unused glade/google_source.ui
* #699: Refactoring of duplicate check handlingg
* #746: Fix accessibility fatals reported by gla11y
* Fixes #730: "Update all subscriptions at startup" overrides "Don't update this feed automatically"
* Fixes #639: Right clicking on article no longer selects it
* #737: Update of Italian translation
* #745: URL fix for French example feeds
* Update inline docs on headline view modes