[BUGFIX] Show warning message if no language is activated

When no language is activated, while updating in the language module,
error messages appear. Show a nice error message that at least one
language must be activated.

Resolves: #72593
Releases: master,7.6
Change-Id: I20459d2f50551f2c1677e04779294feba03a26f1
Reviewed-on: https://review.typo3.org/45751


Reviewed-by: Anja Leichsenring <aleichsenring@ab-softlab.de>
Tested-by: Anja Leichsenring <aleichsenring@ab-softlab.de>
Reviewed-by: Morton Jonuschat <m.jonuschat@mojocode.de>
Tested-by: Morton Jonuschat <m.jonuschat@mojocode.de>