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

Change-Id: I0c4f46d07ec8236925253d82fa6f7a868aa73772
Reviewed-on: https://gerrit.instructure.com/c/canvas-lms/+/293290
Tested-by: Service Cloud Jenkins <9144042a601061f88f1e1d7a1753ea3e2972119d@instructure.com>

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