rails3: fix rescue_action_in_public

Change-Id: I8fb8ca981b52d66a2388386c928e71d45850f66b
Reviewed-on: https://gerrit.instructure.com/30188
Tested-by: Jenkins <jenkins@instructure.com>
Reviewed-by: Cody Cutrer <cody@instructure.com>
Product-Review: Jon Willesen <jonw@instructure.com>
QA-Review: Jon Willesen <jonw@instructure.com>