docs: def command(state, args):
      """Unregister watching regexp for an anime."""
      args = parser.parse_args(args[1:])
      if args.complete:
          query.files.delete_regexp_complete(state.db)
      else:
          if args.aid is None:
              parser.print_help()
          else:
              aid = state.results.parse_aid(args.aid, default_key='db')
              query.files.delete_regexp(state.db, aid)