title: Base64 gif image is not animated inside <feimage>
body: <p>I am using filters to display an animated image inside svg:</p>
  
  <pre><code>&lt;filter id="filter-id1464674757841" width="100%" height="100%" x="0%"y="0%"&gt;
      &lt;feImage xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="data:image/gif;base64,R0lGODl..."&gt;
      &lt;/feImage&gt;
  &lt;/filter&gt;
  </code></pre>
  
  <p>The same image works with the <code>&lt;img/&gt;</code> tag.</p>
  
  <p>Is there any way to make it work inside <code>&lt;feimage&gt;</code> ?</p>
  
  <p>Any help will be appreciated!</p>