l10n: Update git.pot (4 new, 3 removed messages)

Generate po/git.pot from v1.7.12-rc0-54-g9e211, and there are 4 new,
3 removed l10n messages.

 * 4 new messages are added at lines:
   1254, 1264, 1459, 1523

 * 3 old messages are deleted from the previous version at lines:
   1254, 1273, 2854
Signed-off-by: NJiang Xin <worldhello.net@gmail.com>