Merge branch '5.1' into 5.x

* 5.1:
  also reset id readers
  Fix LDAP pagination

Author: fabpot

Form/Type/DoctrineType.php

@@ -244,6 +244,7 @@ public function getParent()
 
     public function reset()
     {
+        $this->idReaders = [];
         $this->entityLoaders = [];
     }