FD3-687 Entidad Pool se setea onDelete SET NULL la relación con SubNet

src/IPv4Bundle/Entity/Pool.php

@@ -73,6 +73,7 @@ class Pool implements TenancyIdTraitInterface, WorkflowInterface
      * @var SubNet $subNet
      *
      * @ORM\ManyToOne(targetEntity="SubNet", inversedBy="ipPool")
+     * @ORM\JoinColumn(onDelete="SET NULL")
      */
     protected $subNet;
 
@@ -86,6 +87,7 @@ class Pool implements TenancyIdTraitInterface, WorkflowInterface
     /**
      * @ORM\ManyToOne(targetEntity="\WorkflowBundle\Entity\Workflow", fetch="EXTRA_LAZY")
      * @ORM\JoinColumn(name="workflow_id", referencedColumnName="id", onDelete="SET NULL")
+     *
      * @JMS\MaxDepth(1)
      */
     protected $workflow;