Fixed helpURI. The old helpURI was incorrect and resulted in wrong helpURI -> 404

Fixed helpURI. The old helpURI was incorrect and resulted in wrong helpURI and a 404 error page, when the end user tried to access the menu item Produkthjelp and got https://MYZIMBRASERVER/help/no/advanced/Zimbra_User_Help.htm which is incorrect

The fix will give you the correct URI:

https://MYZIMBRASERVER/help/en_US/advanced/zimbra_user_help.htm

Tested and verified on Zimbra 8.0.4 (Ubuntu 12.04 LTS)