ubuntu18.04 左上角hot corner 禁用

在应用商店搜索 No Topleft Hot Corner 并安装，设置下就好了

具体问题可参考以下网站：

https://unix.stackexchange.com/questions/196541/remove-disable-hot-corner

https://askubuntu.com/questions/1065973/how-can-i-remove-this-applications-icon-which-does-nothing-on-clicking-either