consent: Give a more informative error message on a passive request.

Since the exception message is now passed back to the SP, the error
should be more informative. This patch change the error message to
indicate that we are unable to give consent on a passive request.

git-svn-id: https://simplesamlphp.googlecode.com/svn/trunk@1576 44740490-163a-0410-bde0-09ae8108e29a

modules/consent/lib/Auth/Process/Consent.php

@@ -182,7 +182,7 @@ class sspmod_consent_Auth_Process_Consent extends SimpleSAML_Auth_ProcessingFilt
 
 		/* User interaction nessesary. Throw exception on isPassive request */	
 		if (isset($state['isPassive']) && $state['isPassive'] == TRUE) {
-			throw new SimpleSAML_Error_NoPassive('noPassive');
+			throw new SimpleSAML_Error_NoPassive('Unable to give consent on passive request.');
 		}
 
 		/* Save state and redirect. */