[TF] Skip check external connectivity (PRODX-5188)

Related-PROD: PRODX-5188
Change-Id: I7012384f5203d11283a6431a45dcc33434f39e18
diff --git a/neutron_tempest_plugin/scenario/test_security_groups.py b/neutron_tempest_plugin/scenario/test_security_groups.py
index dc14857..b18eca8 100644
--- a/neutron_tempest_plugin/scenario/test_security_groups.py
+++ b/neutron_tempest_plugin/scenario/test_security_groups.py
@@ -175,8 +175,10 @@
                 ext_net_ip = subnet['gateway_ip']
                 break
         self.assertTrue(ext_net_ip)
-        self.check_remote_connectivity(server_ssh_clients[0], ext_net_ip,
-                                       servers=servers)
+        # (PRODX-5188) Skip check connectivity with gateway:
+        if not CONF.service_available.contrail:
+            self.check_remote_connectivity(server_ssh_clients[0], ext_net_ip,
+                                           servers=servers)
 
     @decorators.idempotent_id('3d73ec1a-2ec6-45a9-b0f8-04a283d9d864')
     def test_protocol_number_rule(self):