migrate to new iredmail server

==== Required information ====
- iRedMail version: 0.8.6
- Store mail accounts in which backend (LDAP/MySQL/PGSQL): mysql
- Linux/BSD distribution name and version: centos 6.5
- Related log if you're reporting an issue:
====
Recently, I have some problem with iRedmail as I couldn't import the "amavisd" database into the new server.
when I issued this command, it shows the error message as below
# amavisd testkeys
Config file "/etc/amavisd.conf" does not exist, at /usr/sbin/amavisd line 2085.