Updated mediawiki/extensions
Project: mediawiki/extensions/MobileFrontend  7759d35b65db83d573e72a0a59d356858eba880e

Hygiene: Removing a bunch of old icon CSS that is no longer needed

Also fixing logout button so that it stays the same size (24px).

Change-Id: Id41135ea59d7e3e8b8d5cce491d8ab2615890d91