pagekite/Mailpile — pull request #712 by tclancy (2014-06-13 12:53:11+00:00)
Title: Fix Windows error when backup file doesn't fire and rename fails

Trying to run setup on Windows fails on the attempt to rename `mailpile.cfg.new` to `mailpile.cfg` because the file exists. This checks to make sure the file was actually renamed in `backup_file` before attempting to rename.