Better link for changelog on description f-droid

The description of the 33.1.2 version on f-droid gives `https://github.com/nextcloud/android/milestone/126` for the changelog.

`https://github.com/nextcloud/android/milestone/126?closed=1` (`?closed=1` added) would be better as it gives directly the list of fixes and enhancements. Obviously, I have the same suggestion for the next versions 😉

Also, perhaps I misunderstood something but the changelog link within the metadata on f-droid is strange as it speaks about the 3.33.1 version (see `https://github.com/nextcloud/android/blob/HEAD/CHANGELOG.md`nextcloud/android/blob/HEAD/CHANGELOG.md`).