Cannot delete last clarification queue

[eldering]

Description of the problem

When you try to delete on the configuration page the last clarification queue(s), then that fails with the message "No changes made, no changes saved."

Deleting any number of clarification queue(s) works fine as long as there is at least one left after deleting.

Your environment

Current main branch.

[nickygerritsen]

This would (also) be easier with a proper Symfony form.