Pontoon: Update English (Great Britain) (en-GB) localization of AMO
Pontoon: Update English (Great Britain) (en-GB) localization of AMO

Localization authors:
- Ian Neal <iann_bugzilla@blueyonder.co.uk>

mozilla/addons-server,kumar303/addons-server,bqbn/addons-server,bqbn/addons-server,mozilla/olympia,mozilla/addons-server,mozilla/addons-server,wagnerand/addons-server,diox/olympia,wagnerand/addons-server,eviljeff/olympia,kumar303/addons-server,mozilla/addons-server,mozilla/olympia,psiinon/addons-server,bqbn/addons-server,psiinon/addons-server,mozilla/olympia,diox/olympia,kumar303/olympia,kumar303/olympia,eviljeff/olympia,psiinon/addons-server,mozilla/olympia,psiinon/addons-server,kumar303/addons-server,kumar303/olympia,wagnerand/addons-server,kumar303/addons-server,diox/olympia,kumar303/olympia,bqbn/addons-server,diox/olympia,eviljeff/olympia,eviljeff/olympia,wagnerand/addons-server