update en-GB translation
update en-GB translation

Change-Id: I02e5961cad3a73e366d9d2273dfa1cbd169f2530

venturehive/canvas-lms,djbender/canvas-lms,sfu/canvas-lms,grahamb/canvas-lms,sfu/canvas-lms,venturehive/canvas-lms,sfu/canvas-lms,sfu/canvas-lms,grahamb/canvas-lms,grahamb/canvas-lms,SwinburneOnline/canvas-lms,grahamb/canvas-lms,SwinburneOnline/canvas-lms,sfu/canvas-lms,SwinburneOnline/canvas-lms,venturehive/canvas-lms,djbender/canvas-lms,djbender/canvas-lms,sfu/canvas-lms,SwinburneOnline/canvas-lms,sfu/canvas-lms,djbender/canvas-lms,venturehive/canvas-lms,grahamb/canvas-lms