Fix for regex filter when language is unknown

Fix for when with the regex filter, the language is unknown.
It will check now first if its a string.

modules/plex.py

@@ -1822,6 +1822,7 @@ class Plex(Library):
                 has_match = False
                 for reg in filter_data:
                     for name in attrs:
+                        if isinstance(name, str)::
                             if re.compile(reg).search(name):
                                 has_match = True
                 if has_match is False: