spec: fix "should change the default quotas" selenium failure

Change-Id: I90796df43a2e1520273d9056c1bed8fb67923315
Reviewed-on: https://gerrit.instructure.com/45267
Reviewed-by: James Williams  <jamesw@instructure.com>
Tested-by: Jenkins <jenkins@instructure.com>
QA-Review: Jeremy Stanley <jeremy@instructure.com>
Product-Review: Jeremy Stanley <jeremy@instructure.com>