[BUGFIX] Make language module accessible without internet connection

This patch adds the possibility to access the language module without
having an internet connection. You are able to activate and deactivate
languages but trying to update files will give you an error.

Resolves: #75820
Releases: master, 7.6
Change-Id: I27be7f34c76f680a4240e6c75c4a331d96467681
Reviewed-on: https://review.typo3.org/47840


Reviewed-by: Wouter Wolters <typo3@wouterwolters.nl>
Tested-by: Wouter Wolters <typo3@wouterwolters.nl>
Reviewed-by: Morton Jonuschat <m.jonuschat@mojocode.de>
Tested-by: Morton Jonuschat <m.jonuschat@mojocode.de>