fix formatting and nulls in metadata

src/main/java/com/jagrosh/jmusicbot/audio/QueuedTrack.java

@@ -37,13 +37,13 @@ public class QueuedTrack implements Queueable
     public QueuedTrack(AudioTrack track, RequestMetadata rm)
     {
         this.track = track;
-        this.track.setUserData(rm);
+        this.track.setUserData(rm == null ? RequestMetadata.EMPTY : rm);
     }
     
     @Override
     public long getIdentifier() 
     {
-        return track.getUserData(RequestMetadata.class).getOwner();
+        return track.getUserData() == null ? 0L : track.getUserData(RequestMetadata.class).getOwner();
     }
     
     public AudioTrack getTrack()

src/main/java/com/jagrosh/jmusicbot/queue/FairQueue.java

@@ -25,7 +25,8 @@ import java.util.Set;
  * @author John Grosh (jagrosh)
  * @param <T>
  */
-public class FairQueue<T extends Queueable> {
+public class FairQueue<T extends Queueable> 
+{
     private final List<T> list = new ArrayList<>();
     private final Set<Long> set = new HashSet<>();