edit mailinglists

app/UI/Client/DistributionList/Providers/EditListDataProvider.php

@@ -196,7 +196,7 @@ class EditListDataProvider extends AddListDataProvider
         foreach($intMembers as $intMember) {
             $this->data['memberList'][] = $intMember;
         }
-        $allMembers = $intMember + $extMembers;
+        $allMembers = array_merge($intMember, $extMembers);
         foreach($allMembers as $availableMember) {
             $this->data['memberListActually'][$availableMember] = 
             $this->availableValues['memberListActually'][$availableMember] =