1.0.0+kodimov.12: no duplicate TV guide instance; retry the web player registration

- The TV guide setup always wrote instance-settings-91.xml, so on a box
  already set up with another instance (from the original add-on) both read
  channels.m3u8 and every channel showed twice. The setup now rewrites the
  instance that already reads the list, and the service deletes extra ones
  at start (keeps the one that isn't 91, which holds what was watched) and
  restarts IPTV Simple when nothing plays.
- The web player registration for the new servers got one 401 error page
  and gave up, and the TV guide list then lacked LALIGA, DAZN LALIGA and
  Liga de Campeones until the next export 6 hours later. The registration
  is tried 3 times, and after a failure the service exports the list again
  every half hour, up to 6 times.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

README.md

@@ -16,6 +16,7 @@ What it adds:
 - **Extra free channels** in the TV guide list: TVG2 (10) and TeleVigo (15).
 - **The TV guide stays current**: channel list and programme guide re-exported every 6 hours, numbered with Movistar's own dial numbers. Listings come from Movistar (with catch-up links) for its channels and from the public EPG_dobleM guide for the extras.
 - **Gets along with Radios de Vigo** (`service.radios.vigo`), which keeps its own IPTV Simple instance for the Radio section. Kodi only lets *Use channel numbers from backend* be changed while it applies (one PVR instance loaded, or several and *always* on), so with a second instance it had refused the setting. Both add-ons now check it every so often: if it is hidden they turn *always* on, and they turn the setting itself on once; neither ever turns anything off, and turning it off by hand afterwards is respected. They also take turns to restart IPTV Simple, through the `pvr.iptvsimple.restarting` property of Kodi's home window.
+- **One IPTV Simple instance per channel list**: the TV guide setup rewrites the instance that already reads KodiMov+'s list (one set up with the original add-on, or by hand) instead of adding `instance-settings-91.xml` next to it, and the service deletes any extra one at Kodi start (keeping the one that isn't 91, which holds what was watched): two of them showed every channel twice.
 - Fixes the programme guide export of upstream 1.0.0 (the amazon.tv guide is a flat list).
 - Its own proxy port (57031), so it can run next to the original.