ubuntu16.04 desktop提供了VNC server的服务，在Desktop sharing可以直接打开
1、打开desktop sharing，启动
2、勾选 Allow other users to view your desktop
Allow other users to ocntrol your desktop
3、勾选完成之后直接关闭，然后安装dconf-editor
sudo apt install dconf-editor
4、运行dconf-editor
org -> gnome -> desktop -> remote-access
将 “require-encryption”勾选框去掉
5、关闭会后就可以了
