以前为了图安装快，把composer的源改成了国内的：

composer config -g repo.packagist composer https://packagist.phpcomposer.com

今天使用时发现某些composer失败了

感觉需要恢复原始源地址

修改默认源地址指令：

composer config -g repo.packagist composer https://repo.packagist.org

阿里云源地址：

composer config -g repo.packagist composer https://mirrors.aliyun.com/composer/