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

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

mozilla/thimble.mozilla.org,mozilla/thimble.mozilla.org,mozilla/thimble.mozilla.org,mozilla/thimble.mozilla.org