Properly check for version

Author: ericholscher

readthedocs/templates/core/project_list_featured.html

@@ -15,7 +15,9 @@
       </span>
       <ul>
           {% with project.get_stable_version as version %}
+          {% if version %}
             <li><a href="{{ version.get_absolute_url }}">{{ version.slug }}</a></li>
+          {% endif %}
           {% endwith %}
       </ul>
     </span>