Japanese translation (October 2019)

 Hello.
Updated translation for upcoming version 4.14 is in attachment.
messages.pot was taken from git 94170757.

Although it complies finely, it will give us these errors during
compilation:

  error: messages.po:8893: placeholders are incompatible
  error: messages.po:8910: placeholders are incompatible

which points to:

  msgid "% of query"
  msgid "% of table"

However, I believe that they aren't used as placeholders at all. So I've
left them as-is.