null pointer exception in NeutronL3Adapter.getExternalNetworkSubnet()

> 2015-08-20 14:10:06,140 | ERROR | ntDispatcherImpl | EventDispatcher | 400 - org.opendaylight.ovsdb.openstack.net-virt - 1.2.0.SNAPSHOT | Exception in dispatching event NorthboundEvent [handler=NEUTRON_PORT, action=ADD, port=Neu\
tronPort [portUUID=1f781e25-ae88-4210-a296-096a3c04adb4, networkUUID=7d526ede-cfd0-45ec-897f-607471dd801e, name=, adminStateUp=true, status=null, macAddress=FA:16:3E:62:5A:34, fixedIPs=[Neutron_IPs

{ipAddress='172.24.4.55', subnetUUID='9a799aec-5f1\ f-4a2d-b3ed-a109f6c89bcb'}

, Neutron_IPs

{ipAddress='2001:db8::37', subnetUUID='5178fb71-6683-4cf6-a1e7-095da5b9962a'}

], deviceID=3fb41370-be5a-4ba4-8141-e8392d9eb878, deviceOwner=network:router_gateway, tenantID=c079de68c26e4dec9b1867f4af272fb9, se\
curityGroups=[], bindinghostID=, bindingvnicType=normal, bindingvnicType=normal], subnet=null, router=null, routerInterface=null, floatingIP=null, network=null, loadBalancer=null, loadBalancerPool=null, loadBalancerPoolMember=null]
> java.lang.NullPointerException
> at org.opendaylight.ovsdb.openstack.netvirt.impl.NeutronL3Adapter.getExternalNetworkSubnet(NeutronL3Adapter.java:1262)[400:org.opendaylight.ovsdb.openstack.net-virt:1.2.0.SNAPSHOT]
> at org.opendaylight.ovsdb.openstack.netvirt.impl.NeutronL3Adapter.triggerGatewayMacResolver(NeutronL3Adapter.java:1278)[400:org.opendaylight.ovsdb.openstack.net-virt:1.2.0.SNAPSHOT]
> at org.opendaylight.ovsdb.openstack.netvirt.impl.NeutronL3Adapter.handleNeutronPortEvent(NeutronL3Adapter.java:208)[400:org.opendaylight.ovsdb.openstack.net-virt:1.2.0.SNAPSHOT]
> at org.opendaylight.ovsdb.openstack.netvirt.PortHandler.doNeutronPortCreated(PortHandler.java:66)[400:org.opendaylight.ovsdb.openstack.net-virt:1.2.0.SNAPSHOT]
> at org.opendaylight.ovsdb.openstack.netvirt.PortHandler.processEvent(PortHandler.java:161)[400:org.opendaylight.ovsdb.openstack.net-virt:1.2.0.SNAPSHOT]
> at org.opendaylight.ovsdb.openstack.netvirt.impl.EventDispatcherImpl.dispatchEvent(EventDispatcherImpl.java:95)[400:org.opendaylight.ovsdb.openstack.net-virt:1.2.0.SNAPSHOT]
> at org.opendaylight.ovsdb.openstack.netvirt.impl.EventDispatcherImpl.access$200(EventDispatcherImpl.java:28)[400:org.opendaylight.ovsdb.openstack.net-virt:1.2.0.SNAPSHOT]
> at org.opendaylight.ovsdb.openstack.netvirt.impl.EventDispatcherImpl$1.run(EventDispatcherImpl.java:57)[400:org.opendaylight.ovsdb.openstack.net-virt:1.2.0.SNAPSHOT]
> at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:471)[:1.7.0_79]
> at java.util.concurrent.FutureTask.run(FutureTask.java:262)[:1.7.0_79]
> at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)[:1.7.0_79]
> at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)[:1.7.0_79]
> at java.lang.Thread.run(Thread.java:745)[:1.7.0_79]

The corresponding subnet can be created later due to reordering.