Updated mediawiki/extensions/Wikidata
Project: mediawiki/extensions/Wikibase  6f35174a5dbd18413bcbd7ebdc4195d614c012dc

Fix unused/missing private fields and documentation

Fixing obvious typos found by the PHPStorm code analysis.

Change-Id: I1500f10303de8e240009ade8c68cc3380d334a8a