Feature Request: allow not replacing config files

[cat-in-136]

Feature Request: allow not replacing config files

[fraxinas]

it looks like https://github.com/Richterrettich/rpm-rs was abandoned and the project is now continued here: https://github.com/rpm-rs/rpm

this commit implements the %config(noreplace) if i interpret this correctly:
rpm-rs/rpm@66bffe0

[cat-in-136]

mark rpm-crate-issue because %config(noreplace) feature is missing in the current rpm-rs.

[cat-in-136]

@fraxinas thank you for finding out the parameter in rpm-rs!

[cat-in-136]

It has been a long time, today I checked the rpm crate implementation.

To my surprise, %config(missingok) has not introduced to rpm::FileOptionsBuilder. Since %config(noreplace) and %config(missingok) have been treated as two contrasting options in the context of writing rpm spec, I would like to support both of them in same PR.

corresponding rpm spec	cargo-generate-rpm	rpm flags
%config	config = true	rpm::FileFlags::CONFIG
%config(missingok)	n/a (config = "missingok" ?)	rpm::FileFlags::MISSINGOK
%config(noreplace)	n/a (config = "noreplace" ?)	rpm::FileFlags::NOREPLACE