This update for calamares fixes the following issues:

- Reflect the changed path to LiveOS read-only filesystem in KIWI-ng (KIWI 9)
  (boo#1124451).
- BuildRequires libboost_python3-devel for Leap 15.0 and newer
  instead of boost-devel (boo#1124423, upstream issue 817).
- Fix building for openSUSE Leap 42.3 by switching to GCC7.

- Update to Calamares 3.1.11:
  - fix bug then some poorly-configured systems cannot reliably set
    the hardware clock (RTC). Previously this was an error which 
    would abort the entire installation. Calamares now ignores the 
    error.

This update was imported from the openSUSE:Leap:15.0:Update update project.