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/TvDetails/index.tsx

@@ -39,7 +39,6 @@ import StatusBadge from '../StatusBadge';
 const messages = defineMessages({
   firstAirDate: 'First Air Date',
   nextAirDate: 'Next Air Date',
-  userrating: 'User Rating',
   status: 'Status',
   originallanguage: 'Original Language',
   overview: 'Overview',