Update sample_code.adoc

Fixed broken image link.

src/docs/asciidoc/sdk/sample_code.adoc

@@ -59,8 +59,8 @@ The project's assetManager now has access to sample files from the `jme3-test-da
 
 == AssetPacks
 
-
-image::http://jmonkeyengine.org/wp-content/uploads/2010/10/assetpackbrowser-300x166.jpg[assetpackbrowser-300x166.jpg,with="",height="",align="right"]
+[.right]
+image::sdk/assetpackbrowser-300x166.jpg[assetpackbrowser-300x166.jpg,width="",height="",align="right"]
 
 If you need sample 3D models, don't miss the opportunity to download our community-provided <<sdk/asset_packs#,Asset Packs>>!