Fix 403 for / on ocw-origin
Fix 403 for / on ocw-origin

Fix 403 error for 'GET /', observed on AWS QA origin server.
The problem / solution was the one discussed here:
https://stackoverflow.com/questions/19285355/nginx-403-error-directory-index-of-folder-is-forbidden#38046124

mitodl/salt-ops,mitodl/salt-ops