master.mint22

appstream_pool.py: Check for compressed xml, and return source

screenshots if no thumbnails are available.

Encountered these adding the fedora repository, compared to Flathub:
- appstream.xml.gz does not get de-compressed.
- Only source screenshot urls are provided (not pre-sized
  thumbnails).

master.lmde6

appstream_pool.py: Check for compressed xml, and return source

screenshots if no thumbnails are available.

Encountered these adding the fedora repository, compared to Flathub:
- appstream.xml.gz does not get de-compressed.
- Only source screenshot urls are provided (not pre-sized
  thumbnails).

master.mint21

2.3.1

master.lmde5

_flatpak.py: Fix end-of-lifed-with-rebase handling.

This was only marking the eol'd package for removal, but would
fail to add a replacement, as the arguments for add_rebase() were
incorrect.