title: Django sorl-thumbnail display image from url
body: <p>I have working solr-thumbnail in several parts of my project, but this time I want to display an image from a URL, I have it like this:</p>
  
  <pre><code>    {% load thumbnail %}
      {% thumbnail profile_picture_url "150x150" crop="center" as img %}
      &lt;img src="{{ img }}"&gt;
      {% endthumbnail %}
  </code></pre>
  
  <p>The view passes the value profile_picture_url as "http://....image.jpg". The image is correctly displayed if I just use:</p>
  
  <pre><code>&lt;img src="{{ profile_picture_url }}"&gt;
  </code></pre>
  
  <p>What am I doing wrong ?</p>
  
  <p>Thank you</p>