Comment gix_transport::client::blocking_io::ssh::connect

To note that if the `-G` check ever also uses the username, then
that has to be checked to ensure it is safe.

gix-transport/src/client/blocking_io/ssh/mod.rs

@@ -118,6 +118,8 @@ pub fn connect(
                 .stdin(Stdio::null())
                 .with_shell()
                 .arg("-G")
+                // Username affects the stdout from `ssh -G` but may not affect the status. But if
+                // we end up needing it, it can be added here, with a user_argument_safe() check.
                 .arg(url.host_argument_safe().ok_or_else(|| Error::AmbiguousHostName {
                     host: url.host().expect("set in ssh urls").into(),
                 })?),