[Fixed] Made Audiomanager final bc not needed

app/src/main/java/de/yannicpunktdee/yoshibot/audio/AudioPlayerListener.java

@@ -9,7 +9,7 @@ import net.dv8tion.jda.api.managers.AudioManager;
 
 public class AudioPlayerListener implements AudioEventListener {
 	
-	private AudioManager audioManager;
+	private final AudioManager audioManager;
 
 	@Getter
 	private static boolean isPlayingTrack = false;