Fix multiple calls to disconnect

server/server.go

@@ -197,12 +197,13 @@ func (n *Neighbor) Connect() error {
 
 func (n *Neighbor) Disconnect() {
 	log.Infof("%v: Disconnected", n.String())
+	wasConnected := n.Connected
 	n.Connected = false
 	n.State.OpenReceived = false
 	n.tcpconn.Close()
 	n.UpdateState(STATE_IDLE)
 
-	if n.HandlerEvent != nil {
+	if n.HandlerEvent != nil && wasConnected == true {
 		n.HandlerEvent.DisconnectedNeighbor(n)
 	}