fix warning

htdocs/cron/card.php

@@ -284,6 +284,7 @@ if ($conf->use_javascript_ajax) {
 	print '</script>'."\n";
 }
 
+$formconfirm = '';
 if ($action == 'delete') {
 	$formconfirm = $form->formconfirm($_SERVER['PHP_SELF']."?id=".$object->id, $langs->trans("CronDelete"), $langs->trans("CronConfirmDelete"), "confirm_delete", '', '', 1);