网上搜索了一下，从 https://stackoverflow.com/questions/26638238/strange-mysql-popup-mysql-installer-is-running-community-mode 找到了解决方案
Go to Control Panel > System and Security > Administrative Tools and open Task Scheduler.
In the Task Scheduler navigate to Task Scheduler Library > MySQL and select Installer.
From the list at the center of the window right-click ManifestUpdate and select Disable.
It's keeping the MySQL Product Catalog up to date. As described in the documentation,
This option uses the Windows Task Scheduler to schedule a task named "ManifestUpdate". (this is the scheduled task that is disabled the OS way)
Does someone know the internals and how to prevent it from connecting to a remote server?
Start the MySQL installer
Click the wrench image
Uncheck the checkbox to disable automatic updating