[BUGFIX] Give correct information in addLLrefForTCAdescr exception

\TYPO3\CMS\Core\Utility\ExtensionManagementUtility::addLLrefForTCAdescr
needs a non-empty key as first parameter. Otherwise an exception is
thrown but the message shows wrong information.

Resolves: #83532
Releases: master
Change-Id: I59c44b2b4aafcbbee679662ecab667c85f7a25dc
Reviewed-on: https://review.typo3.org/55327


Reviewed-by: Georg Ringer <georg.ringer@gmail.com>
Tested-by: Georg Ringer <georg.ringer@gmail.com>
Tested-by: TYPO3com <no-reply@typo3.com>
Reviewed-by: Mathias Schreiber <mathias.schreiber@typo3.com>
Tested-by: Mathias Schreiber <mathias.schreiber@typo3.com>
Reviewed-by: Wouter Wolters <typo3@wouterwolters.nl>
Tested-by: Wouter Wolters <typo3@wouterwolters.nl>