update cy translation
update cy translation

Change-Id: Icf59bbc2ef6559a05c19672334d710272bdc4973
Reviewed-on: https://gerrit.instructure.com/c/canvas-lms/+/215558
Tested-by: Jenkins

djbender/canvas-lms,sfu/canvas-lms,djbender/canvas-lms,sfu/canvas-lms,djbender/canvas-lms,sfu/canvas-lms,sfu/canvas-lms,djbender/canvas-lms,sfu/canvas-lms,sfu/canvas-lms,sfu/canvas-lms