Revert url conversion.

This is the wrong place to do this per upstream discussion and if
was not able to reproduce an error in testing just now

Author: eileenmcnaughton

vendor/omnipay/paymentexpress/src/Message/PxPayAuthorizeRequest.php

@@ -245,14 +245,4 @@ protected function createResponse($data)
     {
         return $this->response = new PxPayAuthorizeResponse($this, $data);
     }
-
-    /**
-     * Get the request return URL.
-     *
-     * @return string
-     */
-    public function getReturnUrl()
-    {
-        return htmlentities($this->getParameter('returnUrl'));
-    }
 }