[MaNGOS/WotLK] Fix OnFirstLogin

NOTE:
 - Exemple Script can found here http://emudevs.com/showthread.php/1271-First-Login-Script

Signed-off-by: Salja <salja8840@gmail.com>
Merge pull request #45 from Salja2012/master

[MaNGOS/WotLK] Fix OnFirstLogin