Copy of config file breaks upgrade

When there is a copy of the config/config.php, the web updater fails because it cannot create a backup of that file. Most text editors used to edit the config file create backup copies of their own, like config.php~ or config.php.bak. At each upgrade these files have to be removed. This is kind of annoying. Could not the updater just ignore those files?

Its a security check. I think it will Impossible.