Sync: initialize empty array only for combined keys

library/Director/Import/Sync.php

@@ -444,11 +444,11 @@ class Sync
 
     protected function loadExistingObjects()
     {
-        $this->objects = array();
-
         // TODO: Make object_type (template, object...) and object_name mandatory?
         if ($this->hasCombinedKey()) {
 
+            $this->objects = array();
+
             foreach (IcingaObject::loadAllByType(
                 $this->rule->object_type,
                 $this->db