参考链接http://stackoverflow.com/questions/19085807/please-enter-a-commit-message-to-explain-why-this-merge-is-necessary-especially
在vi模式下输入
To solve this:
press “i” write your merge message press “esc” write “:wq” then press enter
“i” is for “insert”, “esc” is the exit the insertion, and “:wq” is just “write” and “quit”.