update nb-x-k12 translation
update nb-x-k12 translation

Change-Id: I508599b07f9dc533b6dd4c1983e6c3e61f87c85c
Reviewed-on: https://gerrit.instructure.com/c/canvas-lms/+/298733
Tested-by: Service Cloud Jenkins <9144042a601061f88f1e1d7a1753ea3e2972119d@instructure.com>

instructure/canvas-lms,sfu/canvas-lms,sfu/canvas-lms,instructure/canvas-lms,sfu/canvas-lms,instructure/canvas-lms,instructure/canvas-lms,instructure/canvas-lms,sfu/canvas-lms,sfu/canvas-lms,sfu/canvas-lms,instructure/canvas-lms,sfu/canvas-lms,instructure/canvas-lms