Updated mediawiki/extensions
Project: mediawiki/extensions/OpenID  29a05117d9191cab420577c57e8c2148971ad221

remove errant backslash in XRDS preamble.

This bit me when I was trying to get Extension:OpenID to work with
OpenID auth on my Gerrit installation.  Since removing this backslash
made it work, I'm assuming that it may fix other bugs elsewhere too.

It is supposed to be a typo, dating back earlier than 2008
(https://gerrit.wikimedia.org/r/gitweb?p=mediawiki/extensions/OpenID.git;a=blob;f=SpecialOpenIDXRDS.body.php;hb=418d1aa02730c2beb037a8bd90d971c830a291c7)

Change-Id: Ida19d8f554b7ce7f5ed2b979cc6221f1de7217e4