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.