Unprivileged users can't use doveadm anymore in 2.3.16

[dovecot at ptld.com]

What happened in 2.3.16 to doveadm? You can no longer use the command as 
an unprivileged user like you could in 2.3.8

Roundcube uses "doveadm pw" to change users passwords and runs as user 
apache. This works in 2.3.8 but in 2.3.16 you get an error.
doveconf: Fatal: Error in configuration file /etc/dovecot/dovecot.conf 
line 19: ssl_key: Can't open file 
/etc/letsencrypt/live/example_cert/privkey.pem: Permission denied

I tried "doveadm quota get ..." from the console as user apache and got 
the same error. I then tried running just "doveadm" and got the error, 
it wouldn't even display the help output. So it appears to not be 
directly related to using the "pw" feature.

Just to trouble shoot i gave full read permission to privkey.pem just to 
see if doveadm would work. Doveadm still would not run for user apache 
but gave a different error:
doveconf: Error: ssl enabled, but ssl_dh not set
doveconf: Fatal: Invalid configuration

Was this requirement to read the privkey.pem always there or just added 
in 2.3.16? Is this a deeper issue considering the ssl_dh error? Is there 
a way to fix this? Is this by design unprivileged user can no longer use 
doveadm?