Switch fork, version going backward

[Emmanuel Dreyfus <manu%netbsd.org@localhost>]

Hello

mail/openarc is bsed on https://github.com/trusteddomainproject/OpenARC
PKGNAME is openarc-20180921

I recently submitted pull request for a bug fix and was told it was 
alrezady fixed on a develop branch, for which releases seems to not
be the priority. I am pointed to a fork that focuses on backporting
fices to a stable release:
https://github.com/flowerysong/OpenARC

I tested switching from the former to the later with success, but there
is a caveat: PKGNAME becomes openarc-1.3.0, which a is a lower version
number than openarc-20180921.

How should that be dealt with?

-- 
Emmanuel Dreyfus
manu%netbsd.org@localhost