[PATCH uci] delta: allow clearing delta path

[Leonardo Mörlein]

Hi all,

Unfortunately this patch has not received much attention yet. I would
like to get some comments on it.

Actually, I plan to use this patch to resubmit a new version of [1].
The proposed change in [1] was only rejected because there was no way
to change the uci configuration from scripts without interfering with
possible uncommitted user changes.

The commit here is my approach to allow changing the uci configuration
from scripts without interfering with possible uncommitted user
changes.

What do you think?

Kind regards,
Leonardo

[1] https://patchwork.ozlabs.org/project/openwrt/patch/20210108012435.175345-1-me@irrelefant.net/