Use already existing reference

Author: fernandobandeira

src/Artistas/PagSeguroRecorrente.php

@@ -82,7 +82,7 @@ public function sendPreApprovalRequest(array $preApprovalRequest)
             'preApprovalExpirationValue'        => $this->sanitizeNumber($preApprovalRequest, 'preApprovalExpirationValue'),
             'preApprovalExpirationUnit'         => $this->sanitize($preApprovalRequest, 'preApprovalExpirationUnit'),
             'maxUses'                           => $this->sanitizeNumber($preApprovalRequest, 'maxUses'),
-            'reference'                         => $this->sanitize($preApprovalRequest, 'preApprovalReference')
+            'reference'                         => $this->reference,
         ];
 
         $this->validatePreApprovalRequest($preApprovalRequest);