Revert code that I erroneously changed

doc/themes/scikit-learn/layout.html

@@ -176,7 +176,8 @@
     <a href="about.html#citing-the-scikit-learn">citing the
     scikit-learn</a>.</p>
 
-    {%- if (toc|length > 20) and (pagename != 'index') %}
+    <!-- it's 11 when it's empty (?) -->
+    {%- if (toc|length == 11) and (pagename != 'index') %}
     <h3>{{ _('This page') }}</h3>
 	{{ toc }}
     {% endif %}