Update git from 2.19.1 to 2.21.0
Update git from 2.19.1 to 2.21.0

release notes: https://raw.githubusercontent.com/git/git/master/Documentation/RelNotes/2.21.0.txt

pypa/manylinux,manylinux/manylinux,pypa/manylinux,pypa/manylinux,manylinux/manylinux