Neutron: Fix the error that qvb and qbr don't have neutron topology
Neutron: Fix the error that qvb and qbr don't have neutron topology

When the Status of VM is "SHUTOFF", the tap node will disappear
we start skydive in this time, the qvb and qbr will not have neutron topology

safchain/skydive,skydive-project/skydive,skydive-project/skydive,lebauce/skydive,lebauce/skydive,skydive-project/skydive,skydive-project/skydive,safchain/skydive,lebauce/skydive,skydive-project/skydive,lebauce/skydive,safchain/skydive,safchain/skydive,lebauce/skydive,safchain/skydive,skydive-project/skydive,skydive-project/skydive,lebauce/skydive,safchain/skydive,safchain/skydive,lebauce/skydive,safchain/skydive,lebauce/skydive