Updated mediawiki/extensions
Project: mediawiki/extensions/FlaggedRevs  a988e3a8c3aea5168dda946576e3b9c031240af5

Fix grammatical error

Spotted by Shirayuki at
https://translatewiki.net/wiki/Thread:Support/About_MediaWiki:Revreview-quality/en

Change-Id: I04cc2b35f953af9a95f69198beaed17580c702fa