Don’t show clusters of checks which are omitted

Lib/fontbakery/reporters/templates/html/section.html

@@ -3,5 +3,7 @@ <h2>{{ section.key[0] | replace("<", "") | replace(">", "") }}</h2>
     {% for status in section.status_summary %}{{ status | emoticon }}{% endfor %}
 </span>
 {% for cluster in section["clustered_checks"] %}
+    {% if cluster is not omitted %}
     {% include "check.html" %}
+    {% endif %}
 {% endfor %}