#185 ALLOW_SSH_PROT_V1 check should skip on OpenSSH 7.6 or later

[David Waring]

SSH v1 protocol and the configuration option were removed from OpenSSH sshd in version 7.6 [1]. This means that there is no Protocol configuration option to check (it's ignored if present in configuration files). Therefore the ALLOW_SSH_PROT_V1 check should be skipped if the running sshd is OpenSSH v7.6 or later.

[1] Release notes at https://www.openssh.com/txt/release-7.6 note the removal which also includes the ssh daemon options.