update en-GB translation
update en-GB translation

Change-Id: I48ff419f83c2b24677d8c73e73dd559c23adb445

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