Explicitly disallow remote hosts to connect to local forwarded ports,
the socks server port in the test suite. This is the default setting
unless a tinkered built ssh is being used.
diff --git a/tests/sshserver.pl b/tests/sshserver.pl
index 103ab14..77cd1f5 100644
--- a/tests/sshserver.pl
+++ b/tests/sshserver.pl
@@ -290,6 +290,7 @@
 Compression no
 ConnectTimeout 20
 ForwardX11 no
+GatewayPorts no
 HostbasedAuthentication yes
 NoHostAuthenticationForLocalhost no
 # Newer OpenSSH options