[sciurus]

The bug for the problem James found with the configuration of Normandy (https://github.com/mozilla/normandy), Mozilla's system for distributing Shield studies , is now public at https://bugzilla.mozilla.org/show_bug.cgi?id=1433134

We were bitten because django's ALLOWED_HOSTS was set to accept anything and django's USE_X_FORWARDED_HOST setting was true.