Fixed broken links.

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

@@ -221,7 +221,7 @@ The link:https://github.com/jMonkeyEngine/wiki/blob/master/src/docs/images/jme3/
 
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-In order to make the hud-frame.png independent of the screen resolution you are using, you could use the `imageMode` attribute on the image element link:http://sourceforge.net/apps/mediawiki/nifty-gui/index.php?title=Resizable_Images_(ImageMode%3Dresize)_explained[ Resizable Images (ImageMode=resize) explained]
+In order to make the hud-frame.png independent of the screen resolution you are using, you could use the `imageMode` attribute on the image element https://versaweb.dl.sourceforge.net/project/nifty-gui/nifty-gui/1.3.2/nifty-gui-the-manual-1.3.2.pdf[Nifty GUI - the Manual: Images (ImageMode=resize)].
 
 [source,xml]
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@@ -232,7 +232,7 @@ In order to make the hud-frame.png independent of the screen resolution you are
 
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-The link:http://hub.jmonkeyengine.org/wiki/lib/exe/fetch.php/jme3:advanced:face1.png[face1.png] image is an image that you want to use as a status icon. Add it to `Interface`.
+The link:https://github.com/jMonkeyEngine/wiki/blob/master/src/docs/images/jme3/advanced/face1.png[face1.png] image is an image that you want to use as a status icon. Add it to `Interface`.
 In the `hud` screen's `foreground` layer, add the following image element:
 
 [source,xml]