mbngs: Let releaseType be None if no type is set

Signed-off-by: Frederik “Freso” S. Olesen <freso.dk@gmail.com>

whipper/common/mbngs.py

@@ -184,8 +184,6 @@ def _getMetadata(release, discid, country=None):
 
     if 'type' in release['release-group']:
         discMD.releaseType = release['release-group']['type']
-    else:
-        discMD.releaseType = u''
     discCredit = _Credit(release['artist-credit'])
 
     # FIXME: is there a better way to check for VA ?

whipper/test/test_common_mbngs.py

@@ -219,7 +219,7 @@ class MetadataTestCase(unittest.TestCase):
         discid = "xu338_M8WukSRi0J.KTlDoflB8Y-"  # disc 4
 
         metadata = mbngs._getMetadata(response['release'], discid)
-        self.assertEqual(metadata.releaseType, u'')
+        self.assertEqual(metadata.releaseType, None)
 
     def testAllAvailableMetadata(self):
         """Check that all possible metadata gets assigned."""