Updated mediawiki/extensions
Project: mediawiki/extensions/WikiForum  80ea699b0b5ca1052b6509ef9ccb1e4c1cafffe5

Fix bug with the WikiForumList tag

Looked like a copy-paste remnant, $this instead of $thread, and remove an
unused variable.

Spotted by Severin Anatoliy

Change-Id: Ib514eb5520498a9d9201b8b1aa819806e5eaf998