Update index.html

Fix for http://www.html5gamedevs.com/topic/33682-getting-error-babylonguiadvanceddynamictexture-is-undefined/

Playground/zipContent/index.html

@@ -6,10 +6,10 @@
         <title>Babylon.js sample code</title>
         <!-- Babylon.js -->
         <script src="https://www.babylonjs.com/hand.minified-1.2.js"></script>
+        <script src="https://preview.babylonjs.com/babylon.js"></script>
         <script src="https://preview.babylonjs.com/gui/babylon.gui.min.js"></script>
         <script src="https://preview.babylonjs.com/cannon.js"></script>
         <script src="https://preview.babylonjs.com/oimo.js"></script>
-        <script src="https://preview.babylonjs.com/babylon.js"></script>
         
         <style>
             html, body {