Merge pull request #111 from andig/fix-move-aggregator

Fix middleware error when adding group with children to aggregator

lib/Volkszaehler/Model/Aggregator.php

@@ -90,7 +90,7 @@ protected function contains(Entity $entity, $recursive = FALSE) {
 
 		if ($recursive) {
 			foreach ($this->children as $child) {
-				if ($child->contains($entity, $recursive)) {
+				if ($child instanceof Aggregator && $child->contains($entity, $recursive)) {
 					return TRUE;
 				}
 			}