Git报错: OpenSSL SSL_connect: SSL_ERROR_SYSCALL in connection to github.com:443

在使用Git来克隆仓库报了错误，如下：

fatal: unable to access ‘https://github.com/xiaobingchan/machine_learn/‘: OpenSSL SSL_connect: SSL_ERROR_SYSCALL in connection to github.com:443

解决方案： 

git config --global --add remote.origin.proxy ""