pkg/51510: url2pkg github inconsistency

[prlw1%cam.ac.uk@localhost]

>Number:         51510
>Category:       pkg
>Synopsis:       url2pkg github inconsistency
>Confidential:   no
>Severity:       non-critical
>Priority:       low
>Responsible:    pkg-manager
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Mon Sep 26 09:45:00 +0000 2016
>Originator:     Patrick Welche
>Release:        NetBSD-7.99.39/amd64 and pkgsrc-current
>Organization:
>Environment:
>Description:
Thanks to reading url2pkg code, I could work out the url to use to grab a particular commit from github:

# url2pkg https://github.com/opencv/opencv/archive/7f14a278a71b065baf53340f7181c5cc62dc722e.tar.gz
Use of uninitialized value $gh_release in string ne at /usr/pkg/bin/url2pkg line 367, <SITES> line 299.
url2pkg> Running "make distinfo" ...
=> Bootstrap dependency digest>=20010302: found digest-20160304
WARNING: [license.mk] Every package should define a LICENSE.
===> Skipping vulnerability checks.
WARNING: No /var/db/pkg/pkg-vulnerabilities file found.
WARNING: To fix run: `/usr/pkg/sbin/pkg_admin -K /var/db/pkg fetch-pkg-vulnerabilities'.
=> Fetching 7f14a278a71b065baf53340f7181c5cc62dc722e.tar.gz
Requesting https://github.com/opencv/7f14a278a71b065baf53340f7181c5cc62dc722e.tar.gz
ftp: Error retrieving file `404 Not Found'

url2pkg then tries to grab a different one...
>How-To-Repeat:

>Fix: