mpd: Tweak docstring, add PR#1213 to changelog

docs/changelog.rst

@@ -50,6 +50,10 @@ MPD frontend
 - The MPD command ``count`` now ignores tracks with no length, which would
   previously cause a :exc:`TypeError`. (PR: :issue:`1192`)
 
+- Concatenate multiple artists, composers and performers using the "A;B" format
+  instead of "A, B". This is a part of updating our protocol implementation to
+  match MPD 0.19. (PR: :issue:`1213`)
+
 Utils
 -----
 

mopidy/mpd/translator.py

@@ -93,7 +93,7 @@ def track_to_mpd_format(track, position=None, stream_title=None):
 
 def concat_multi_values(models, attribute):
     """
-    Format mopidy model values for output to MPD client.
+    Format Mopidy model values for output to MPD client.
 
     :param models: the models
     :type models: array of :class:`mopidy.models.Artist`,