deluge: Fix app installation on Debian testing

On Debian stable, mark deluge app as not available because deluge-web is not working in this distribution.

• Default deluged configuration directory location changed. I didn't do migration from the old location because deluge app hasn't been working on Debian stable.
• Make deluge-web systemd service start after deluged service to prevent Connection Manager popup in deluge-web after system reboot.

Tests performed:

• On Debian stable:
  • Deluge app is not installable from the app page.
  • All functional tests are skipped.
• On Debian testing:
  • All tests pass.
  • After reboot, deluge-web service started after deluge service and there is no Connection Manager popup in deluge web UI.
  • Changing torrent download directory works.

Closes #2322 (closed).

Signed-off-by: Veiko Aasa veiko17@disroot.org