fixed TestMusicPlayer to corectly initialize audioContext

git-svn-id: https://jmonkeyengine.googlecode.com/svn/trunk@8957 75d07b2b-3a1a-0410-a2c5-0572b91ccdca

engine/src/test/jme3test/audio/TestMusicPlayer.java

@@ -63,6 +63,7 @@ public class TestMusicPlayer extends javax.swing.JFrame {
         ar = JmeSystem.newAudioRenderer(settings);
         ar.initialize();
         ar.setListener(listener);
+        AudioContext.setAudioRenderer(ar);
     }
 
     /** This method is called from within the constructor to