修改debian9 stretch源

修改debian9 stretch源

修改配置文件/etc/apt/sources.list

修改成163源：

    deb http://mirrors.163.com/debian/ stretch main non-free contrib
    deb http://mirrors.163.com/debian/ stretch-updates main non-free contrib
    deb http://mirrors.163.com/debian/ stretch-backports main non-free contrib
    deb-src http://mirrors.163.com/debian/ stretch main non-free contrib
    deb-src http://mirrors.163.com/debian/ stretch-updates main non-free contrib
    deb-src http://mirrors.163.com/debian/ stretch-backports main non-free contrib
    deb http://mirrors.163.com/debian-security/ stretch/updates main non-free contrib
    deb-src http://mirrors.163.com/debian-security/ stretch/updates main non-free contrib

修改成清华源：

deb https://mirrors.tuna.tsinghua.edu.cn/debian/ stretch main non-free contrib
deb https://mirrors.tuna.tsinghua.edu.cn/debian/ stretch-updates main non-free contrib
deb https://mirrors.tuna.tsinghua.edu.cn/debian/ stretch-backports main non-free contrib
deb-src https://mirrors.tuna.tsinghua.edu.cn/debian/ stretch main non-free contrib
deb-src https://mirrors.tuna.tsinghua.edu.cn/debian/ stretch-updates main non-free contrib
deb-src https://mirrors.tuna.tsinghua.edu.cn/debian/ stretch-backports main non-free contrib
deb https://mirrors.tuna.tsinghua.edu.cn/debian-security/ stretch/updates main non-free contrib
deb-src https://mirrors.tuna.tsinghua.edu.cn/debian-security/ stretch/updates main non-free contrib

修改成科大源:

deb http://mirrors.ustc.edu.cn/debian/ stretch main non-free contrib
deb http://mirrors.ustc.edu.cn/debian/ stretch-updates main non-free contrib
deb http://mirrors.ustc.edu.cn/debian/ stretch-backports main non-free contrib
deb-src http://mirrors.ustc.edu.cn/debian/ stretch main non-free contrib
deb-src http://mirrors.ustc.edu.cn/debian/ stretch-updates main non-free contrib
deb-src http://mirrors.ustc.edu.cn/debian/ stretch-backports main non-free contrib
deb http://mirrors.ustc.edu.cn/debian-security/ stretch/updates main non-free contrib
deb-src http://mirrors.ustc.edu.cn/debian-security/ stretch/updates main non-free contrib