monitoring: Use the groupsummary query for the host group summary view

refs #8241

modules/monitoring/library/Monitoring/DataView/Hostgroupsummary.php

@@ -17,4 +17,12 @@ class Hostgroupsummary extends Groupsummary
     {
         return array('hostgroup', 'hostgroup_alias');
     }
+
+    /**
+     * {@inheritdoc}
+     */
+    public static function getQueryName()
+    {
+        return 'groupsummary';
+    }
 }