This update for webkit2gtk3 fixes the following issues:

- Update to version 2.28.3 (bsc#1173998):
+ Enable kinetic scrolling with async scrolling.
+ Fix web process hangs on large GitHub pages.
+ Bubblewrap sandbox should not attempt to bind empty paths.
+ Fix threading issues in the media player.
+ Fix several crashes and rendering issues.
+ Security fixes: CVE-2020-9802, CVE-2020-9803, CVE-2020-9805,
CVE-2020-9806, CVE-2020-9807, CVE-2020-9843, CVE-2020-9850,
CVE-2020-13753.

This update was imported from the SUSE:SLE-15:Update update project.