$unrar = ['unrar-nonfree']; Missing in fresh install

==== Required information ====
- iRedMail version: 0.9.1
- Store mail accounts in which backend (LDAP/MySQL/PGSQL): MySQL
- Web server (Apache or Nginx): Nginx
- Linux/BSD distribution name and version: Ubuntu 14.04
- Related log if you're reporting an issue: n/a
====

I just did fresh install of 0.9.1 and $unrar = ['unrar-nonfree']; is missing from /etc/amavis/conf.d/50-user.

Thanks