Pass wantsurl through to the jump session function, so it can inform the other...

Pass wantsurl through to the jump session function, so it can inform the other application we are doing SSO with where it wants to go. Fixes #1644

htdocs/auth/xmlrpc/jump.php

@@ -49,7 +49,7 @@ require_once(get_config('libroot') .'institution.php');
 
 $remotewwwroot = param_variable('wr');
 $instanceid    = param_variable('ins');
-$wantsurl      = '';
+$wantsurl      = param_variable('wantsurl');
 
 if (!get_config('enablenetworking')) {
     throw new XmlrpcClientException('Sorry - networking has been disabled for this Mahara site.');
@@ -62,11 +62,11 @@ $url = $remotewwwroot.$peer->application->ssolandurl;
 $providers = get_service_providers($USER->authinstance);
 $approved  = false;
 
-$url = start_jump_session($peer, $instanceid);
+$url = start_jump_session($peer, $instanceid, $wantsurl);
 
 if (empty($url)) {
     throw new XmlrpcClientException('DEBUG: Jump session was not started correctly or blank URL returned.'); // TODO: errors
 }
 redirect($url);
 
-?>
\ No newline at end of file
+?>