Update artist image download message and lyrics plugin URL

app/store/artists.py

@@ -25,9 +25,9 @@ class ArtistStore:
         ARTIST_LOAD_KEY = instance_key
 
         print("Loading artists... ", end="")
-        cls.artists.extend(
-            get_all_artists(TrackStore.tracks, AlbumStore.albums)
-        )
+        cls.artists.clear()
+
+        cls.artists.extend(get_all_artists(TrackStore.tracks, AlbumStore.albums))
         print("Done!")
         for artist in ardb.get_all_artists():
             if instance_key != ARTIST_LOAD_KEY: