[FEATURE] Added an exception, if any invalid TYPO3 language is choosen.

Resolves: #57560


git-svn-id: https://svn.typo3.org/TYPO3v4/Extensions/lfeditor/trunk@85431 735d13b6-9817-0410-8766-e36946ffe9aa
[TASK] Release of version 2.11


git-svn-id: https://svn.typo3.org/TYPO3v4/Extensions/lfeditor/trunk@85432 735d13b6-9817-0410-8766-e36946ffe9aa