Update devel/libgit2 to 0.27.0 required for gitlab 10.7.x

[mfechner]

Summary

Commit message:
Update devel/libgit2 to 0.27.0 required for gitlab 10.7.x

Reviewed by: tz/swills (mentor)
Approved by: tz/swills (mentor), wg (maintainer)
Differential Revision: URL to this revision

Test Plan

All patches are build, you can find all build logs:
https://pkg.fechner.net/jail.html?mastername=111amd64-gitlab

The fresh packages are tested against a new installation using:
https://gitlab.fechner.net/mfechner/Gitlab-vagrant

An old version is updated following the manual:
https://gitlab.fechner.net/mfechner/Gitlab-docu

[tz]

Why did you remove the patches? If you do so you should mention the reason in the commit log. Most times upstream incorporated them, but not always.

[mfechner]

No patch was removed, the files upstream changed the directory, that is the reason why the filename of the patches have been changed (make makepatch).

[swills]

Looks OK to me, would be good to mention why patches were removed in commit message.