Fix Artist.album() to return special albums (#896)

Author: JonnyWong16

plexapi/audio.py

@@ -180,7 +180,7 @@ def album(self, title):
             Parameters:
                 title (str): Title of the album to return.
         """
-        key = '/library/metadata/%s/children' % self.ratingKey
+        key = f"/library/sections/{self.librarySectionID}/all?artist.id={self.ratingKey}&type=9"
         return self.fetchItem(key, Album, title__iexact=title)
 
     def albums(self, **kwargs):