[Dovecot] minor director issues

[Cor Bosman]

> Oops, not CRC32, but a 32bit hash based on MD5 of the username. Still,
> it's 32bit so with lots of users there will be a lot of collisions
> (which shouldn't be a problem, except doveadm director map will list
> users who haven't really logged in).

Isn't it possible to keep a copy of the username with the md5 checksum?
Or is that problematic because of the collisions? 

Cor