l10n: po-id for 2.36 (round 2)

Translate following new components:
  * setup.c
  * split-index.c
  * strbuf.c
  * trailer.c

Also delete obsolete strings.

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

Author: bagasme