Shib13: Fix valid-session detection.

git-svn-id: https://simplesamlphp.googlecode.com/svn/trunk@1489 44740490-163a-0410-bde0-09ae8108e29a

www/shib13/idp/SSOService.php

@@ -130,7 +130,7 @@ if(SimpleSAML_Auth_Source::getById($idpmetadata['auth']) !== NULL) {
  * endpoint - then the session is authenticated and set, and the user is redirected back with a RequestID
  * parameter so we can retrieve the cached information from the request.
  */
-if (!$session->isAuthenticated($authority) ) {
+if (!$session->isValid($authority) ) {
 
 	$authId = SimpleSAML_Utilities::generateID();
 	$session->setAuthnRequest('shib13', $authId, $requestcache);