Updated mediawiki/extensions
Project: mediawiki/extensions/MobileFrontend  24374f12d1ad74f4909273c69e1b14ffd938156d

Lots of minor fixes

* Unused vars
* echo void
* Class calling its descendant's function

Change-Id: I5b3a370515117c1c6766eedcfd933bf0b6e4f760