Fix entry referencing merge-request, not issue number in changelog

In commit cc580fb3, a recent changelog entry was changed from referencing a merge-request (!) to referencing an issue (#). Probably because it looked liked a typo. However, this made the changelog entry to point to an unrelated issue instead of the actual merge-request of the change.

Note that no issue was previously opened for the changelog entry as it was a feature request on Discord.