update en-GB translation
update en-GB translation

Change-Id: I9dcc446a173b13a1f32be25bda0cbe0a4389a44b

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