应用场景：当你有一个存在的git仓库，需要关联新的远程仓库，可以进行如下操作：
[fly@fly-vm libbmp]$ git remote rm origin
[fly@fly-vm libbmp]$ git remote -v
[fly@fly-vm libbmp]$ git remote add origin https://gitee.com/c-program/libbmp.git
[fly@fly-vm libbmp]$ git remote -v
origin https://gitee.com/c-program/libbmp.git (fetch)
origin https://gitee.com/c-program/libbmp.git (push)
