Failed to update qos when port cannot find network
Issue Description:
Could not get network by port's network id, so we cannot use the network to get qos.
java.lang.NullPointerException: null
at org.opendaylight.netvirt.qosservice.QosNeutronUtils.getQosPolicy(QosNeutronUtils.java:811)
at org.opendaylight.netvirt.qosservice.QosNeutronPortChangeListener.checkForPortIpAddressUpdate(QosNeutronPortChangeListener.java:123)
Signed-off-by: Ning Zhang <zhangninglc@inspur.com>
Change-Id: Id3df070ebbdfd90952e9cc8b5d021803a2911dd7