入口左下角设置：
https://mirror.bit.edu.cn/qtproject/online/qtsdkrepository/windows_x86/root/qt/
https://mirrors.ustc.edu.cn/qtproject/online/qtsdkrepository/windows_x86/root/qt/
https://mirrors.ustc.edu.cn/qtproject/online/qtsdkrepository/mac_x64/root/qt/
附各国的qt镜像站点
https://download.qt.io/static/mirrorlist/