Updated mediawiki/extensions
Project: mediawiki/extensions/DeleteBatch  49d336d656a6ca47f65e2deb10f47eefdf258c5b

Clarify from form/file

Reported by Niklas at <https://translatewiki.net/wiki/Thread:Support/About_MediaWiki:Deletebatch-processing-from-form/en>

Change-Id: Idee9383de3946144edfb81536d1bdddf6e12713c