update en-GB translation
update en-GB translation

Change-Id: I073b755bf6f983a92f4937d0f2d9131973ac4f14

dgynn/canvas-lms,HotChalk/canvas-lms,djbender/canvas-lms,grahamb/canvas-lms,sfu/canvas-lms,instructure/canvas-lms,fronteerio/canvas-lms,matematikk-mooc/canvas-lms,SwinburneOnline/canvas-lms,sfu/canvas-lms,fronteerio/canvas-lms,venturehive/canvas-lms,instructure/canvas-lms,sfu/canvas-lms,dgynn/canvas-lms,SwinburneOnline/canvas-lms,sfu/canvas-lms,sfu/canvas-lms,djbender/canvas-lms,grahamb/canvas-lms,matematikk-mooc/canvas-lms,venturehive/canvas-lms,dgynn/canvas-lms,instructure/canvas-lms,sfu/canvas-lms,SwinburneOnline/canvas-lms,sfu/canvas-lms,dgynn/canvas-lms,fronteerio/canvas-lms,grahamb/canvas-lms,instructure/canvas-lms,instructure/canvas-lms,matematikk-mooc/canvas-lms,HotChalk/canvas-lms,HotChalk/canvas-lms,instructure/canvas-lms,venturehive/canvas-lms,grahamb/canvas-lms,grahamb/canvas-lms,SwinburneOnline/canvas-lms,fronteerio/canvas-lms,instructure/canvas-lms,HotChalk/canvas-lms,venturehive/canvas-lms,matematikk-mooc/canvas-lms,djbender/canvas-lms,djbender/canvas-lms