Bug#975555: sshguard on buster does not work.

[Pat Suwalski]

Package: sshguard

Upon upgrading to buster, sshguard in all of my deployments has stopped 
working.

I suspect this line in the Debian changelog:

  * debian/sshguard.service, Use nft instead iptables.

There doesn't seem to be any obvious way to change this back to iptables.

It is unclear why a change that clearly breaks existing installs was put 
into the package.

Is there a straightforward way to change it back? I have no plans to use 
nft across my large deployment.

Thanks,
--Pat