l10n: zh_CN.po: translate 68 messages (2194t0f0u)

Translate 68 new messages came from git.pot update in 727b957
(l10n: git.pot: v1.8.5 round 1 (68 new, 9 removed)).

Signed-off-by: Jiang Xin <worldhello.net@gmail.com>