Fixed broken image links.

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

@@ -199,7 +199,7 @@ See also link:https://versaweb.dl.sourceforge.net/project/nifty-gui/nifty-gui/1.
 === Add Images
 
 The
-<<../images/jme3/advanced/start-background.png,start-background.png>> image is a fullscreen background picture. Add it to `Interface`. In the `start` screen, add the following image element:
+link:https://github.com/jMonkeyEngine/wiki/blob/master/src/docs/images/jme3/advanced/start-background.png[start-background.png] image is a fullscreen background picture. Add it to `Interface`. In the `start` screen, add the following image element:
 
 [source,xml]
 ----
@@ -210,7 +210,7 @@ The
 
 ----
 
-The link:http://hub.jmonkeyengine.org/wiki/lib/exe/fetch.php/jme3:advanced:hud-frame.png[hud-frame.png] image is a transparent frame that we use as HUD decoration. Add it to `Interface`. In the `hud` screen, add the following image element:
+The link:https://github.com/jMonkeyEngine/wiki/blob/master/src/docs/images/jme3/advanced/hud-frame.png[hud-frame.png] image is a transparent frame that we use as HUD decoration. Add it to `Interface`. In the `hud` screen, add the following image element:
 
 [source,xml]
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