Pontoon: Update Sorbian, Lower (dsb) localization of AMO Frontend
Pontoon: Update Sorbian, Lower (dsb) localization of AMO Frontend

Localization authors:
- Michael Wolf <milupo@sorbzilla.de>

kumar303/addons-frontend,mozilla/addons-frontend,mozilla/addons-frontend,tsl143/addons-frontend,kumar303/addons-frontend,mozilla/addons-frontend,tsl143/addons-frontend,tsl143/addons-frontend,tsl143/addons-frontend,kumar303/addons-frontend,kumar303/addons-frontend,mozilla/addons-frontend