add a wait threshold timer instead of timer.sleep(1)

[arcolife]

TODO comments in src/pbft-core/pbft-sim-engine/pbftserverengine.go

	// TODO: change listenready to switch case assertion and kill-timer clock
	for i := 0; i < cfg.N; i++ {
		<-svList[i].Nd.ListenReady
	}

	time.Sleep(1 * time.Second) // wait for the servers to accept incoming connections
	for i := 0; i < cfg.N; i++ {
		svList[i].Nd.SetupReady <- true // make them to dial each other's RPCs
	}

	// TODO: change listenready to switch case assertion and kill-timer clock
	//fmt.Println("[!!!] Please allow the program to accept incoming connections if you are using Mac OS.")
	time.Sleep(1 * time.Second) // wait for the servers to accept incoming connections