fix(lang): correct strings for library sync button & user import toast (#1252)

* fix(lang): 'scan plex libraries' should actually be 'sync'

* fix(lang): also fix user import string in case of no imported users

* fix(lang): remove unused 'User Rating' strings

src/components/MovieDetails/index.tsx

@@ -35,7 +35,6 @@ import StatusBadge from '../StatusBadge';
 
 const messages = defineMessages({
   releasedate: 'Release Date',
-  userrating: 'User Rating',
   status: 'Status',
   revenue: 'Revenue',
   budget: 'Budget',