libgit2/libgit2 v1.6.2 on GitHub

What's Changed

remote: always populate old id in update tips by @ethomson in #6506
The update tips callback would not always be properly provided with an empty (0000000...) OID for new refs.
Revert #6503 by @ethomson in #6511
The certificate callback added port information for callbacks in #6503, but the format was ambiguous with IPv6 addresses. Revert this change temporarily.
Add git_odb_backend_loose back by @ethomson in #6512
During SHA256 refactoring, the git_odb_backend_loose API was accidentally removed. Add it back.
meta: configure pkg-config .pc correctly by @ethomson in #6514
During SHA256 refactoring, the pkg-config .pc file was erroneously renamed to git2 instead of libgit2. Repair this.

Full Changelog: v1.6.1...v1.6.2