Plaintext logins with Dovecot and Ubuntu

Disallow plaintext authentication in non-SSL mode?

Webmin permits you to enable non-SSL connections on its Dovecot SSL Configuration page, but on Ubuntu at least, that edits /etc/dovecot/dovecot.conf by changing 'yes' here to 'no':

disable_plaintext_auth = no

but the same thing also has to be done in /etc/dovecot/dovecot-postfix.conf ... manually for now.