fix spacing issues for webm source in applyclass.html

effects/applyclass/popcorn.applyclass.html

@@ -51,8 +51,8 @@
         type='video/ogg; codecs="theora, vorbis"'> 
         
       <source id='webm'
-      src="../../test/trailer.webm"
-      type='video/webm; codecs="vp8, vorbis"'>
+        src="../../test/trailer.webm"
+        type='video/webm; codecs="vp8, vorbis"'>
 
       <p>Your user agent does not support the HTML5 Video element.</p>