[L10N] Startup of Git 2.3.0 l10n round 1

Hi,

Since Git v2.3.0-rc0 had already been released, it's time to start new round
of git l10n. This time there are 13 new messages need to be translated since
last update for v2.2.0:

    l10n: git.pot: v2.3.0 round 1 (13 new, 11 removed)

    Generate po/git.pot from v2.3.0-rc0 for git v2.3.0 l10n round 1.

    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