Corrected RODEX message size (#3966)

* Fixes #3959.
* Increased the size of the mail message to 500 characters on the main SQL file.
Thanks to @Indigo000!

sql-files/main.sql

@@ -781,7 +781,7 @@ CREATE TABLE IF NOT EXISTS `mail` (
   `dest_name` varchar(30) NOT NULL default '',
   `dest_id` int(11) unsigned NOT NULL default '0',
   `title` varchar(45) NOT NULL default '',
-  `message` varchar(255) NOT NULL default '',
+  `message` varchar(500) NOT NULL default '',
   `time` int(11) unsigned NOT NULL default '0',
   `status` tinyint(2) NOT NULL default '0',
   `zeny` int(11) unsigned NOT NULL default '0',