MongoDB: Selectable if necessary packages not installed

I am able to select "MongoDB" as my "LongTermCache" in the settings, but the system does not check if i have the necessary packages installed.

If the packages are not installed i get a Fatal Error:

[30-Apr-2020 11:19:25 Europe/Berlin] PHP Fatal error:  Uncaught Error: Class 'MongoDB\Client' not found in .../packages/quiqqer/quiqqer/lib/QUI/Cache/LongTermCache.php:223

Then i can no longer access the backend or frontend because everything crashes and i have to manually change the config via config file edit.