指定SSH秘钥算法

使用ssh协议从gerrit服务器克隆代码时，会出现错误：

$ Unable to negotiate with gerrit-server port 29418: no matching key exchange method found. Their offer: diffie-hellman-group1-sha1
fatal: Could not read from remote repository.

解决办法是指定ssh的秘钥算法。新建或编辑文件 ~/.ssh/config ，添加如下内容

Host gerritserver
    KexAlgorithms +diffie-hellman-group1-sha1