cas: Make it easier to override finalStep() in subclasses.

This patch makes it easier to override the finalStep()-function in
subclasses by making sure that the casValidation()-function can be used
from subclasses.

Patch by Josselin Jacquard.

git-svn-id: https://simplesamlphp.googlecode.com/svn/trunk@2886 44740490-163a-0410-bde0-09ae8108e29a

modules/cas/lib/Auth/Source/CAS.php

@@ -151,7 +151,7 @@ class sspmod_cas_Auth_Source_CAS  extends SimpleSAML_Auth_Source  {
 	 * @param string $service
 	 * @return list username and attributes
 	 */
-	private function casValidation($ticket, $service){
+	protected function casValidation($ticket, $service){
 		switch($this->_validationMethod){
 			case 'validate':
 				return  $this->casValidate($ticket, $service);