Updated mediawiki/extensions
Project: mediawiki/extensions/LiquidThreads  9e4c258681bad3ca45f05b980c33d756d2014f2e

Only show search form if LuceneSearch is detected

As far as I know Lucene is the only engine that supports it.
I haven't been able to test this change as I do not have Lucene installed.

Change-Id: I7615dd926c33873524fae8837f923fef52e7b1c0