Register color "not set" saved to xml

[Gert Kello]

Hi.

I upgraded to 2.4 (Windows) and played a little with this new version...

After that I compared the gnucash xml files before and after. I
noticed that every account I have modified has slot with color "not
set" assigned:

    <slot>
      <slot:key>color</slot:key>
      <slot:value type="string">Not Set</slot:value>
    </slot>

Is it by purpose? I do not like the extra data in file... In addition
to making file larger it also makes comparing changes harder.  (I use
non-compressed xml format and store the file in svn repository).

Gert