发现在执行 react-native init ProjectName 的时候，会从git://github.com/feackbook/react.git里下载一些内容信息，但如果在无网络下就会出现以下错误信息，有无办法解决此问题？
This will walk you through creating a new React Native project in /Users/stff/project/HelloWord
npm ERR! git fetch -a origin (git://github.com/facebook/react.git) fatal: unable to connect to github.com:
npm ERR! git fetch -a origin (git://github.com/facebook/react.git) github.com[0: 192.30.252.131]: errno=Network is unreachable
npm ERR! git fetch -a origin (git://github.com/facebook/react.git) github.com[1: 192.30.252.130]: errno=Network is unreachable
npm ERR! git fetch -a origin (git://github.com/facebook/react.git) github.com[2: 192.30.252.129]: errno=Network is unreachable