Issue between roundcube and newer dovecot 2.3.16 with doveadm pw

[dovecot at ptld.com]

Aki;

I know most likely this isn't dovecot's fault, however upgrading from 
2.3.8 to 2.3.16 broke the password plugin for roundcube. Im only asking 
if you might know what changes in dovecot might have caused this 
incompatibility so i can fix it myself or point roundcube in the right 
direction to fix it.

I submitted a bug report to roundcube with details of the issue.
https://github.com/roundcube/roundcubemail/issues/8200