By default Roundcube changed pass to MD5, which is awful.
Here I'm upping that to SSHA512 for systems which support it using `doveadm pw` internals.

/usr/sbin/dovecotpw:[executable] (chmod +x)

#!/bin/bash

/usr/bin/doveadm pw "$*"

The above is required as Dovecot 2 phased out the separate binary for dovecotpw, and instead ships it within doveadm. Roundcube Password plugin by default cannot accept `doveadm pw` or its full path so it has to be wrapped by the above.

The following lines have to be changed:
roundcube/plugins/password/config.inc.php:

$config['password_query'] = "UPDATE vmail.mailbox SET password=%D,passwordlastchange=NOW() WHERE username=%u LIMIT 1";
$config['password_dovecotpw'] = '/usr/bin/dovecotpw';
$config['password_dovecotpw_method'] = 'SSHA512';