Fixes an error deleting an endpoint group project

Deleting a endpoint group project fails because the router specifies
a controller method that doesn't exist. This returns a 500 error to
the user for what should be a successful operation.

Change-Id: I3b91d8023d31555893fb944da73633a69d8e286f
Closes-bug: #1377304
Merge "Fixes an error deleting an endpoint group project" into proposed/juno