Drives the canvas renderable so that something has a chance to be renderer with JOGL 2.0

git-svn-id: https://jmonkeyengine.googlecode.com/svn/trunk@9903 75d07b2b-3a1a-0410-a2c5-0572b91ccdca

engine/src/jogl/com/jme3/system/jogl/JoglAbstractDisplay.java

@@ -140,6 +140,9 @@ public abstract class JoglAbstractDisplay extends JoglContext implements GLEvent
 
         animator.start();
         wasAnimating = true;
+        
+        //FIXME not sure it is the best place to do that
+        renderable.set(true);
     }
 
     protected void onCanvasAdded() {