[BUGFIX] Correct message when language is missing

Message in User settings has to refer to the Language module
instead of the Extension Manager.

Resolves: #63449
Releases: master, 6.2
Change-Id: I6865330281b77336595af6e056975974ec700c15
Reviewed-on: http://review.typo3.org/34814
Reviewed-by: Jigal van Hemert <jigal.van.hemert@typo3.org>
Tested-by: Jigal van Hemert <jigal.van.hemert@typo3.org>