Recent Debian (and Devuan) releases have disabled ssh and rsh protocols as possible transfer method of packages. The solution to permit them again is to re-enable them in apt configuration file.

Create your own config file /etc/apt/apt.conf.d/30-ssh-transport and paste the following:

Dir::Bin::Methods::rsh "rsh";
Dir::Bin::Methods::ssh "ssh";

Package transport over both protocols should be re-enabled now.