Remove -webkit-overflow-scrolling: touch rule to fix iOS app-bar issues
Remove -webkit-overflow-scrolling: touch rule to fix iOS app-bar issues

Fixes #4825, but reverts fix for #2279.

indirectlylit/kolibri,mrpau/kolibri,indirectlylit/kolibri,lyw07/kolibri,learningequality/kolibri,learningequality/kolibri,mrpau/kolibri,lyw07/kolibri,learningequality/kolibri,indirectlylit/kolibri,mrpau/kolibri,lyw07/kolibri,lyw07/kolibri,mrpau/kolibri,indirectlylit/kolibri,learningequality/kolibri