Updated mediawiki/extensions
Project: mediawiki/extensions/AbuseFilter  ddb57635bede9f3e0f46fcdbeadf686938426558

SpecialAbuseLog: use DifferenceEngine::addHeader to render diffs

Not sure why it wasn't used, maybe because it does a little more
than the bare minimum we need here.

Change-Id: I5e604474849d1389fc4cc260c76cf80e4e466bf5