Check for _any_ ancestors when finding width

This statement changes the width of the descendants block when there are
also ancestors. This was relying on `direct_ancestors`, which is
particular data required for displaying `all_ancestors`.

This checks `all_ancestors` instead, which is more pertinent.

Author: meshy

cbv/templates/cbv/klass_detail.html

@@ -83,7 +83,7 @@ <h2>Ancestors (<abbr title="Method Resolution Order">MRO</abbr>)</h2>
             {% endif %}
 
             {% if all_children %}
-                <div id="descendants" class="span{% if direct_ancestors %}8{% else %}12{% endif %}">
+                <div id="descendants" class="span{% if all_ancestors %}8{% else %}12{% endif %}">
                     <h2>Descendants</h2>
                     <ul class="unstyled">
                         {% for child in all_children %}