Nevermind. I think I still see an issue here for users who has never saved Webmin Bind module config.
Anyone with CentOS 7 needs to make sure that /etc/webmin/bind8/config file has the following directives added at the end of the file before installing Webmin 2.001 upgrade:
auto_chroot=
chroot=
We will try to fix that issue for 2.002 release.