update en-GB translation
update en-GB translation

Change-Id: I3920271e0f88e98abebb20f40e88478b8dde43b4

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