update pt-BR translation
update pt-BR translation

Change-Id: I94b38ba1c6eac2b7de760c8e6a758455c91cdaf3
Reviewed-on: https://gerrit.instructure.com/c/canvas-lms/+/226761
Tested-by: Service Cloud Jenkins <9144042a601061f88f1e1d7a1753ea3e2972119d@instructure.com>

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