Move task out of ctor to avoid initialisation ordering issues

osu.Game/OsuGame.cs

@@ -293,6 +293,8 @@ namespace osu.Game
             var nextBeatmap = beatmap.NewValue;
             if (nextBeatmap?.Track != null)
                 nextBeatmap.Track.Completed += currentTrackCompleted;
+
+            nextBeatmap?.LoadBeatmapAsync();
         }
 
         private void currentTrackCompleted()