1080p migration tweak

some minor tweaks, ideally we should use a transaction but due to the way our code is.. its more hassle than its worth (why fix this one part when we really need it used all over)
* Add some logging to each 1080p migration part so people see some sort of progress in their console
* Use show_id instead of tvdb_id for first part of migration, just in case there is a duplicate id or if show is missing tvdbid (never know)
* Optimize query by reducing the arithmetic performed each time