ipaclient_setup_ssh: Keep no_ for prefix for settings, use ssh_trust_dns

The no_ prefix for the ssh and sshd settings has been added back. The
naming of the settings should be the same all over the ipcalient role.
The exception is sssd here as it has been deprected and is used from
ipaclient_test.

The name for the setting ssh_trust_dns has been fixed to the command line
option name and not the internl optinos name.