CORD-3143 Set port.service_instance

Change-Id: Iea4c91dd19a48745aa5b5051f82be77588667a87
diff --git a/xos/synchronizer/tests/test_pull_ports.py b/xos/synchronizer/tests/test_pull_ports.py
index 7bfe160..c6a3cb3 100644
--- a/xos/synchronizer/tests/test_pull_ports.py
+++ b/xos/synchronizer/tests/test_pull_ports.py
@@ -83,6 +83,7 @@
             self.assertEqual(saved_port.ip, "1.2.3.4")
             self.assertEqual(saved_port.mac, "11:22:33:44:55:66")
             self.assertEqual(saved_port.port_id, 2111)
+            self.assertEqual(saved_port.service_instance, xos_instance)