MFH: r534921

www/gitea: Fix viewing of branches with a slash in the name

An issue[0] was filed upstream in January that branches with a slash in
their name (e.g. stable/11) result in a 500 error when attempting to view
them.

I tracked down the issue to the fact that read(2) on a directory fd in
FreeBSD will actually succeed, while it will not on Linux/other OS. I have
filed a PR[1] with go-git to remedy the problem there, and then we
(hopefully) convince gitea maintainers to accept the patch as well once it's
upstreamed.

The attached patch brings it into the ports tree as well, so that FreeBSD
users can more immediately get the fix. It should still apply to the version
in 2020Q2, more or less, with version numbers changed to protect the
innocent.

[0] https://github.com/go-gitea/gitea/issues/9938
[1] https://github.com/go-git/go-git/pull/39

PR: 245863
Approved by: <stb lassitu de> (maintainer)
Aoorived by: koobs (mentor, ports)

Approved by: ports-secteam (blanket: minor bugfix patch)