[L10N] Kickoff for Git 2.20.0 round 3

Hi,

Git v2.20.0-rc2 has been released, and there are 5 new messages need to
be translated. So let's start new round of l10n for Git 2.20.0. See commit:

    l10n: git.pot: v2.20.0 round 3 (5 new, 3 removed)

    Generate po/git.pot from v2.20.0-rc2 for git v2.20.0 l10n round 3.

    Signed-off-by: Jiang Xin [off-list ref]

You can get it from the usual place:

    https://github.com/git-l10n/git-po/

As how to update your XX.po and help to translate Git, please see
"Updating a XX.po file" and other sections in “po/README" file.

--
Jiang Xin