Fixed broken link.

src/docs/asciidoc/jme3/advanced/nifty_gui.adoc

@@ -61,7 +61,7 @@ Nifty GUIs are made up of the following *elements*:
 === JME-Nifty Sample Code
 
 *  XML examples
-**  link:http://code.google.com/p/jmonkeyengine/source/browse/trunk/engine/test-data/Interface/Nifty/HelloJme.xml[HelloJme.xml]
+**  link:https://github.com/jMonkeyEngine/jmonkeyengine/blob/master/jme3-testdata/src/main/resources/Interface/Nifty/HelloJme.xml[HelloJme.xml] - Can be found in <<sdk/sample_code#jme3testdata-assets#,jme-testdata/Interface/Nifty>> also.
 
 *  Java examples
 **  link:http://code.google.com/p/jmonkeyengine/source/browse/trunk/engine/src/test/jme3test/niftygui/TestNiftyGui.java[TestNiftyGui.java]