Avoid updating the config-file if nothing changed. This also prevents creating
the file and config-directory if the default is used and no config-file existed
yet.
`config.Save()` performs various steps (creating the directory, updating
or copying permissions, etc etc), which are not needed if the defaults are
used; a445d97c25/cli/config/configfile/file.go (L135-L176)
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
f87d7ed864