When looking at the new (unmerged) version of the tool in https://github.com/wmde/Lizenzhinweisgenerator/tree/welance I noticed an unnecessary comma in the attribution.
When using https://commons.wikimedia.org/wiki/File:FIFA-Headquarter.jpg as example image, the attribution generated by the old version looks like this:
But the attribution generated by the new version adds another comma:

