Removed .ogg extension from audio MEDIA_MANAGER.

There is some historical controversy about the .ogg extension and what
you should expect from it. It's better to let the audio and video
plugins take the sniffing-based route to find out what it really seems
to be.

mediagoblin/media_types/audio/__init__.py

@@ -22,4 +22,4 @@ MEDIA_MANAGER = {
     'processor': process_audio,
     'sniff_handler': sniff_handler,
     'display_template': 'mediagoblin/media_displays/audio.html',
-    'accepted_extensions': ['mp3', 'flac', 'ogg', 'wav', 'm4a']}
+    'accepted_extensions': ['mp3', 'flac', 'wav', 'm4a']}