Updated mediawiki/extensions
Project: mediawiki/extensions/Translate  0b9c6e970a8fa12d5de612f88ef506a6b689bb6e

Add option 'skipgroup' to manageMessageChanges.php

Plan to use this in update-externals in the translatewiki repo, to exclude
ext- from being processed. This should make the command run about twice as
quickly, because there are no expected changes in ext-*.

Change-Id: Ibb1f38ead8377bd31a2b4521c9e0e5f90bb038da