Exit goroutine when connection is not WebSocket

main.go

@@ -56,6 +56,7 @@ func main() {
 		con, err := upgrader.Upgrade(w, r, nil)
 		if err != nil {
 			log.Println(err)
+			return
 		}
 		var quit = make(chan bool)
 		con.SetCloseHandler(func(code int, text string) error {