set notifications and settings as unsharded for rails 3

Change-Id: Ibbb21e3cf61b55a02af924dddb5d9836efdb257a
Reviewed-on: https://gerrit.instructure.com/29428
Reviewed-by: Cody Cutrer <cody@instructure.com>
Tested-by: Jenkins <jenkins@instructure.com>
Product-Review: James Williams  <jamesw@instructure.com>
QA-Review: James Williams  <jamesw@instructure.com>