This update for libqt4 fixes the following issues:

* Fix buffer over-read in read_xbm_body (boo#1176315, CVE-2020-17507)
* Fix "double free or corruption" in QXmlStreamReader (boo#1118595, CVE-2018-15518)
* Fix QBmpHandler segfault on malformed BMP file boo#1118596, CVE-2018-19873)
* Fix crash when parsing malformed url reference (boo#1118599, CVE-2018-19869)


This update was imported from the openSUSE:Leap:15.1:Update update project.