Updated mediawiki/extensions
Project: mediawiki/extensions/TimedMediaHandler  a38666f6d0bdf8374d3ba220d66461b25cafea3b

Use PHP's built-in class_exists instead of MWInit::classExists

MWInit::classExists is deprecated as of 1.22 in favor of the
class_exists PHP built-in.

Change-Id: I8b73a273296c9382600aaa0fa45df31849d076b7