fix pseudonyms_controller_spec rescue_action_in_public! calls for rails3

Change-Id: I610b1dd45b2554e50370a4a5a90ffb4937fc581e
Reviewed-on: https://gerrit.instructure.com/30073
Tested-by: Jenkins <jenkins@instructure.com>
Reviewed-by: Jon Willesen <jonw@instructure.com>
Product-Review: Landon Wilkins <lwilkins@instructure.com>
QA-Review: Landon Wilkins <lwilkins@instructure.com>