Get ${OSREL} at install time

Hello all,

net/gitup uses a reinplace cmd to setup gitup.conf to the correspondent
RELEASE/STABLE for command `gitup release` and `gitup stable`.
So, if user is using 13.1-RELEASE, reinplace will configure gitup.conf to:

"release" : {
                "branch"           : "releng/13.1",
"stable" : {
                "branch"           : "stable/13",

The problem is that OSREL is taken from build time and at this moment 13.2
pkgs are being built on a 13.1 machine.
So the result is wrong by setting releng/13.1 instead of releng/13.2.

the reinplace cmd is:
---
${REINPLACE_CMD} -e 's|stable\/12|stable\/${OSREL:R}| ; \
                s|releng\/11.4|releng\/${OSREL}|' \
                ${WRKSRC}/gitup.conf
---

Any sugestion or example that permits to get OSREL at install time?

Thanks,

-- 
Nuno Teixeira
FreeBSD Committer (ports)