Still sending keep alive for node that has been removed from Controller

[Jon Carstens]

I had a node on the network and then ran Grizzly.Network.reset_controller() which cleared everything.

But zipgateway is still handling keep alive ACK from the removed nodes

87029185 Sending DISCOVER
87029185 DHCP pass completed
87029185 update flag 0x1 0x85
87030012 node_input_queued: Packet for DTLS_PORT uip_len: 61
87030012 ClassicZIPNode_dec_input: pkt: 23 3 len: 3
87030012 Sending keep alive ACK from z-wave node 11 to port:40522 of IP:fd00:aaaa::2dcc:f922:934:2e64