Updated mediawiki/extensions
Project: mediawiki/extensions/TwitterCards  e9d1a273914fa734a93e2277fb20b97eef3ead09

Make PageImages extension optional

Since images aren't required for summary cards, it doesn't make sense to
require the PageImages extension.

Change-Id: Ib7f30334141a6783e6202c8266732785482a2487