Autosave feature may cause unwanted commit if commit message buffer loses focus

[izaera]

This is related to https://github.com/diiq/atomatigit/issues/108

If you have autosave active, when you press 'c' to commit you are presented with a commit message buffer. If you change focus to another buffer or application (like, f.e: a terminal) in the middle of message composition, the buffer gets autosaved and atomatigit performs the commit.