Revert "rails3: fix erubis for messages"

This reverts commit f91d65639aadbd7d41714e9183711fd39c028a4a.

Change-Id: I8af64741607c2647f2e9488884c5831b6d7c6cfc
Reviewed-on: https://gerrit.instructure.com/30012
Tested-by: Jenkins <jenkins@instructure.com>
Reviewed-by: Jon Willesen <jonw@instructure.com>
Product-Review: Cameron Matheson <cameron@instructure.com>
QA-Review: Cameron Matheson <cameron@instructure.com>