UseRoaming is deprecated, only check on older versions

UseRoaming was deprecated in OpenSSH 7.2, see this commit:

openssh/openssh-portable@a306863

This PR adds a condition so the control checks only on
older version.

Fixes #121

Signed-off-by: Sebastian Gumprich <github@gumpri.ch>

Author: Sebastian Gumprich

controls/ssh_spec.rb

@@ -219,6 +219,7 @@
   impact 1.0
   title 'Client: Do not allow Roaming'
   desc 'Workaround for SSH Client Bug CVE-2016-0777 and CVE-2016-0778'
+  only_if { ssh_crypto.ssh_version < 7.2 }
   describe ssh_config do
     its('UseRoaming') { should eq('no') }
   end