Update Useful-links.html (mrdoob#23396)

removed "Fast HTML5 game development using three.js" from the list. As the following link don't have any relevant doc or video(as mentioned)

docs/manual/en/introduction/Useful-links.html

@@ -149,9 +149,6 @@ <h2>Old Links</h2>
 		<li>
 			[link:http://www.slideshare.net/yomotsu/webgl-and-threejs WebGL and Three.js] by [link:https://github.com/yomotsu Akihiro Oyamada] (slideshow).
 		</li>
-		<li>
-			[link:http://bkcore.com/blog/general/adobe-user-group-nl-talk-video-hexgl.html Fast HTML5 game development using three.js] by [link:https://github.com/BKcore BKcore] (video).
-		</li>
 		<li>
 			<a href="https://www.youtube.com/watch?v=VdQnOaolrPA" target="_blank">Trigger Rally</a>  by [link:https://github.com/jareiko jareiko] (video).
 		</li>