Pontoon: Update Japanese (ja) localization of MDN
Pontoon: Update Japanese (ja) localization of MDN

Localization authors:
- Kohei Yoshino <kohei.yoshino@gmail.com>

jwhitlock/kuma,SphinxKnight/kuma,Elchi3/kuma,safwanrahman/kuma,jwhitlock/kuma,a2sheppy/kuma,SphinxKnight/kuma,SphinxKnight/kuma,mozilla/kuma,safwanrahman/kuma,jwhitlock/kuma,SphinxKnight/kuma,SphinxKnight/kuma,a2sheppy/kuma,escattone/kuma,safwanrahman/kuma,mozilla/kuma,a2sheppy/kuma,jwhitlock/kuma,safwanrahman/kuma,Elchi3/kuma,escattone/kuma,jwhitlock/kuma,mozilla/kuma,a2sheppy/kuma,a2sheppy/kuma,escattone/kuma,mozilla/kuma,safwanrahman/kuma,mozilla/kuma,Elchi3/kuma,safwanrahman/kuma,SphinxKnight/kuma,Elchi3/kuma,Elchi3/kuma