fix paging

mopidy_youtube/backend.py

@@ -94,16 +94,16 @@ class YouTubeLibraryProvider(backend.LibraryProvider):
             query = {
                 'part': 'id,snippet',
                 'fields': 'nextPageToken,items(snippet(resourceId(videoId)))',
-                'maxResults': maxresults,
+                'maxResults': 50,
                 'playlistId': id,
                 'key': yt_key,
                 'pageToken': page,
             }
             results = session.get(yt_api_endpoint + 'playlistItems',
-                                  params=query).json()['items']
-            for res in results:
+                                  params=query).json()
+            for res in results['items']:
                 video_ids.append(res['snippet']['resourceId']['videoId'])
-            page = results['nextPageToken'] or None
+            page = results.get('nextPageToken') or None
         return self._get_tracks(video_ids)
 
     def _get_search(self, query, maxresults=20):