Graceful-shutdown not supported

[leftyb]

Even though the node signaled that it is gracefully shutting down, the LB still sends REGISTER to it which will lead to keep some session in memory and prevent the shutdown.

[leftyb]

Logs
https://app.box.com/files/0/f/12056786922/SipServlets_GracefulShutdownNotworking_12_11_2016

[deruelle]

The node is sending a property GRACEFUL_SHUTDOWN to the LB but the LB is not checking this property and thus not doing anything with it such as saying keep existing traffic on the node and divert new traffic to other nodes.

[knosach]

@deruelle updated
23b0a1e