In the ASArch meeting there was a request that setup-ssh should also update the
user's known_hosts file so that running the ssh(1) later would not prompt the
user (asking if the host is trusted). Note this is not needed for
create-node-ssh to work, since it adds the host as a known host to it's
in-memory host list. This only impacts the first use of ssh(1).
There was a dissenting opinion that setup-ssh should not do this – it should
only do the bare minimum for GlassFish.