git-state leaves an empty color section in config files

[Brickster]

When git-state prints the status section in color it needs to write to the color.ui configuration. If the user didn't have any other color settings, the section is left empty in the config. Each execution adds a new empty section.

After five executions the local config file might look like this:

[git-state "reflog"]
        show = false
[color]
[color]
[color]
[color]
[color]