SDK:

- fix in nifty cleanup threading

git-svn-id: https://jmonkeyengine.googlecode.com/svn/trunk@8729 75d07b2b-3a1a-0410-a2c5-0572b91ccdca

sdk/jme3-gui/src/com/jme3/gde/gui/multiview/NiftyPreviewPanel.java

@@ -273,6 +273,12 @@ public class NiftyPreviewPanel extends PanelView {
 
     public void cleanup() {
         offPanel.stopPreview();
+        SceneApplication.getApplication().enqueue(new Callable<Object>() {
+
+            public Object call() throws Exception {
                 nifty.exit();
+                return null;
+            }
+        });
     }
 }