Windows installer deletes Storj’s auth file

[jkawamoto]

The Windows installer runs the uninstaller if it finds an old version of this app is installed, i.e. updating the app. The uninstaller deletes Storj's auth file but after the updating installation, and thereby sync-storj cannot login to Storj.

I'd be better to keep Storj's auth file until the uninstaller supports to check the process is a part of updating or actual uninstallation.