Prevent a notice message from showing up.

git-svn-id: file:///tmp/wdn_thm_drupal/branches/drupal-7.x@146 20a16fea-79d4-4915-8869-1ea9d5ebf173

sites/all/modules/unl/unl_cas.module

@@ -9,6 +9,7 @@ function unl_cas_init()
 {
     require_once dirname(__FILE__) . '/unl_loader.php';
     unl_load_zend_framework();
+    drupal_session_start();
 	
 	$cas = unl_cas_get_adapter();