Restart network container when container's configure is changed.

Fix #2099

I could improve this by figuring out if the network related configuration is changed, then decided if restart network container or not. But thought the user expects a blackout time during configuration update anyway.  
Yeah when there are several containers in a pod, and more than one container with new configurations. If only one has changed, we only kill it once. I could optimize that like what I mentioned in pr description but thought not necessary since we plan to replace network container soon.