Fix SAML-Toolkits#275 Remove unnecesary call

Author: pitbulk

lib/Saml2/Auth.php

@@ -568,8 +568,6 @@ public function buildRequestSignature($samlRequest, $relayState, $signAlgorithm
             );
         }
 
-        $key = $this->_settings->getSPkey();
-
         $objKey = new XMLSecurityKey($signAlgorithm, array('type' => 'private'));
         $objKey->loadKey($key, false);