more example in example

As this file is an example, it could help people to learn golang pattern. So, i've added another way to get a clock signal. I've kept the original to show people 2 different ways.

Former-commit-id: d5b50c0845e93388a41863fb262b166320c2735c

_examples/websocket/connectionlist/main.go

@@ -77,7 +77,7 @@ func main() {
 
 	go func() {
 		i := 0
-		for {
+		for range time.Tick(1*time.Second){ //another way to get clock signal
 			mutex.Lock()
 			broadcast(Conn, fmt.Sprintf("aaaa2 %d\n", i))
 			mutex.Unlock()