MAGETWO-45594: XSS code still can be saved into database

- Fixed bug in iframe constructor

Author: Alexander Makeev

app/code/Magento/Paypal/Block/Iframe.php

@@ -89,10 +89,10 @@ public function __construct(
         $this->_hssHelper = $hssHelper;
         $this->_orderFactory = $orderFactory;
         $this->_checkoutSession = $checkoutSession;
-        parent::__construct($context, $data);
         $this->_isScopePrivate = true;
         $this->readFactory = $readFactory;
         $this->reader = $reader;
+        parent::__construct($context, $data);
     }
 
     /**