l10n: zh_CN.po: translate 3 new messages
l10n: zh_CN.po: translate 3 new messages

Translate 3 new messages for upcoming git 1.7.10.3.

Signed-off-by: Jiang Xin <61b5e6324abee2d58ba2cf49f31c723faf6fd946@gmail.com>

destenson/git,destenson/git,destenson/git,destenson/git,destenson/git,destenson/git,destenson/git,destenson/git