Updated mediawiki/extensions
Project: mediawiki/extensions/MobileFrontend  50b0c96bf42e0e502f6ab9838c37702d954ffcd3

Fix the header buttons on watchlist

Also split up the mediawiki-ui-group rules so it is clearer for
what purpose they serve.

Bug: 60923
Change-Id: I3c5e922913a5964f1dfd4fe903edd29367b69f56