Updated mediawiki/extensions
Project: mediawiki/extensions/MobileFrontend  5f3fd952dc45144b80c2c7a07e13abc6e2386b5c

Completely remove the $wgMFCustomLogos['logo'] stuff

It's been broken for a long time and doesn't comply with our current
designs anyway. Remove mw.png and don't default the mobile logo to it:
it's too small for our current usage of mobile logo and it's kinda pointless
to use a MW logo there.

Change-Id: I5501842553334e93cb67f213df7bc898fd7e2802