Update RefundController.php

@see Payum#25

Author: NiMeDia

src/Payum/PayumModule/Controller/RefundController.php

@@ -20,7 +20,7 @@ public function doAction()
             $gateway->execute(new Refund($token));
         } catch (ReplyInterface $reply) {
             if ($reply instanceof HttpRedirect) {
-                $this->redirect()->toUrl($reply->getUrl());
+                return $this->redirect()->toUrl($reply->getUrl());
             }
 
             if ($reply instanceof HttpResponse) {
@@ -36,6 +36,6 @@ public function doAction()
             throw new \LogicException('Unsupported reply', null, $reply);
         }
 
-        $this->redirect()->toUrl($token->getAfterUrl());
+        return $this->redirect()->toUrl($token->getAfterUrl());
     }
 }