Fix sample video source url

After upgrade videojs 5.x, the video sample source url was changed.

Author: yoonsy

example.html

@@ -23,9 +23,9 @@
     </div>
 
     <video id="video1" class="video-js vjs-default-skin vjs-big-play-centered" height="300" width="600" controls data-setup="{}">
-      <source src="http://video-js.zencoder.com/oceans-clip.mp4" type='video/mp4' />
-      <source src="http://video-js.zencoder.com/oceans-clip.webm" type='video/webm' />
-      <source src="http://video-js.zencoder.com/oceans-clip.ogv" type='video/ogg' />
+      <source src="http://vjs.zencdn.net/v/oceans.mp4" type='video/mp4'>
+      <source src="http://vjs.zencdn.net/v/oceans.webm" type='video/webm'>
+      <source src="http://vjs.zencdn.net/v/oceans.ogv" type='video/ogg'>
       <p class="vjs-no-js">To view this video please enable JavaScript, and consider upgrading to a web browser that
         <a href="http://videojs.com/html5-video-support/" target="_blank">supports HTML5 video</a></p>
     </video>