Updated mediawiki/extensions
Project: mediawiki/extensions/CentralAuth  dcf1d2c3e7459b2de101941dbd4235acd858172b

MWInit::classExists -> class_exists

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

Change-Id: I0764c08e49d8f1f8adfac269c86c4ba226170611