Don't grab focus with non-actionable table.
Don't grab focus with non-actionable table.

Fixes OUT-2569

Test Plan:
- On the Outcomes page of a course, click on the Manage Rubrics button
  in the top right
- Click on one of the listed rubrics
- Tab through the page and verify that the rubric is not focused between
  the Settings link of the course nav and the Edit Rubric button

Change-Id: Ifffc196f1242218f9aab23bdc8df651be03f5d51
Reviewed-on: https://gerrit.instructure.com/172737
Tested-by: Jenkins
Reviewed-by: Augusto Callejas <7d9b9fd126d23d111f693e51511b33ea0e7192f6@instructure.com>
QA-Review: Nathan Nuclear <2e8aa918660411855c6d44d5bb2da677aa033255@instructure.com>
Product-Review: Nathan Nuclear <2e8aa918660411855c6d44d5bb2da677aa033255@instructure.com>

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