Doveadm error since 2.3.11.3 when run as unprivileged user

I allow users to run 'doveadm' for mailbox maintenance (to expunge
mail for instance). Since the upgrade to 2.3.11.3, this no longer
works and results in the following error message:

doveconf: Fatal: Error in configuration file
/etc/dovecot/conf.d/10-ssl.conf line 13: ssl_key: Can't open file
/etc/ssl/private/de-korte.org.key: Permission denied

This is no surprise, as non-privileged users are not allowed to read
the private keys of the server. Question is, why is doveadm trying to
read this key in the first place (it is not needed for mailbox
maintenance) and why is it failing now?

Regards, Arjen