Fix grammar in de.xml
Fix grammar in de.xml

Resolves #4952

Reported-by: Dennis Kraffczyk <64b2b6d12bfe4baae7dad3d018f8cbf6b0e7a044@dennis-kraffczyk.de>

WoltLab/WCF,WoltLab/WCF,WoltLab/WCF,WoltLab/WCF