Updated mediawiki/extensions
Project: mediawiki/extensions/Wikibase  a878c60c573125a606241c56fee60b4e21337821

Don't try to fetch non-existing extension data from ParserOutput

wikibase-configvars is not used and nothing saved there,
since we instead add this stuff to the JS config vars directly.

Change-Id: I2f1fc63118dab4cc1d5a8124785658d21bacbd02