[COMMITTED] ja_JP: Change the offset for Taisho gan-nen from 2 to 1 [BZ #24162]

[Rafal Luzynski]

Thank you for your contribution, TAMUKI-san.  You don't need to post
the patch again if you commit the same patch which had been posted
before, or if changes are minor.  Also, if you remove ChangeLog from
your patch before posting then you don't have to remove it if the
patch is committed.

Otherwise perfect.

Regards,

Rafal