Change wrong extended template

Resources/views/Block/block_stats.html.twig

@@ -9,7 +9,7 @@ file that was distributed with this source code.
 
 #}
 
-{% extends "SonataBlockBundle:Block:block_core_rss.html.twig" %}
+{% extends sonata_block.templates.block_base %}
 
 {% block block %}
     <!-- small box -->
@@ -26,4 +26,4 @@ file that was distributed with this source code.
             {{ 'stats_view_more'|trans({}, 'SonataAdminBundle') }} <i class="fa fa-arrow-circle-right"></i>
         </a>
     </div>
-{% endblock %}
+{% endblock %}