Updated mediawiki/extensions
Project: mediawiki/extensions/MobileFrontend  cffba576971b8a6b688044608d8741d0a7f77d8b

QA: Fix broken browser tests

* KeepGoing was visiting the login page not the signup page
* Other tests broken due to reference to LoginPage rather than
SpecialUserLoginPage

Change-Id: Ic6f2c69f6a13527c38ee3a4ec18ef622679eef85