Server: Allow column idea_id to be NULL

warden_server/warden_3.0.sql

@@ -70,7 +70,7 @@ CREATE TABLE IF NOT EXISTS `events` (
   `client_id` int UNSIGNED NOT NULL,
   `data` longtext NOT NULL,
   `valid` tinyint UNSIGNED NOT NULL DEFAULT '1',
-  `idea_id` varchar(255) NOT NULL UNIQUE,
+  `idea_id` varchar(255) UNIQUE,
   PRIMARY KEY (`id`),
   KEY `id` (`id`,`client_id`),
   KEY `received` (`received`)