fragile AssignmentSettingsView qunit spec

fixes CNVS-10218

test plan:
 - specs should pass ... always forever

Change-Id: Ida3fc8191184a569c7728689f0da02a43d45b39b
Reviewed-on: https://gerrit.instructure.com/29020
Reviewed-by: Bryan Madsen <bryan@instructure.com>
QA-Review: Bryan Madsen <bryan@instructure.com>
Product-Review: Bryan Madsen <bryan@instructure.com>
Reviewed-by: Matthew Irish <mirish@instructure.com>
Tested-by: Bryan Madsen <bryan@instructure.com>