ONOS-2843 Fix bug post NBI subnet get an error.

Change-Id: I93b52a0c69a57b458b610afbb78cfdec0b50e3a5
diff --git a/apps/vtnrsc/src/main/java/org/onosproject/vtnrsc/virtualport/impl/VirtualPortManager.java b/apps/vtnrsc/src/main/java/org/onosproject/vtnrsc/virtualport/impl/VirtualPortManager.java
index a94ea1f..e0c49f5 100644
--- a/apps/vtnrsc/src/main/java/org/onosproject/vtnrsc/virtualport/impl/VirtualPortManager.java
+++ b/apps/vtnrsc/src/main/java/org/onosproject/vtnrsc/virtualport/impl/VirtualPortManager.java
@@ -30,6 +30,7 @@
 import org.onosproject.store.service.StorageService;

 import org.onosproject.vtnrsc.AllowedAddressPair;

 import org.onosproject.vtnrsc.BindingHostId;

+import org.onosproject.vtnrsc.DefaultVirtualPort;

 import org.onosproject.vtnrsc.FixedIp;

 import org.onosproject.vtnrsc.SecurityGroup;

 import org.onosproject.vtnrsc.SubnetId;

@@ -98,7 +99,8 @@
                                                  BindingHostId.class,

                                                  SecurityGroup.class,

                                                  SubnetId.class,

-                                                 IpAddress.class))

+                                                 IpAddress.class,

+                                                 DefaultVirtualPort.class))

                 .build().asJavaMap();

         log.info("Started");

     }