Upgrade JGit to v126.96.36.199711221230-r
There are several fixes for git repos on NFS file systems and races with
git gc operations. The initial approach was to backport those fixes to
JGit's 4.1 branch and you can find those changes at . Using the 4.5
branch became the preferred approach when other Gerrit community members
noted that they use Gerrit 2.12 in production with JGit 4.5.