l10n: zh_CN.po: translate 5 messages (2135t0f0u)

Translate 5 new messages came from git.pot update in b8ecf239
(l10n: git.pot: v1.8.4 round 2 (5 new, 3 removed)).
Signed-off-by: NJiang Xin <worldhello.net@gmail.com>