edx/edx-platform — pull request #5708 by wedaly (2014-10-23 19:48:37+00:00)
Title: Logistration: Use a 403 status to indicate that the user does not have a linked account

It turns out that if you use a 401 and basic auth is enabled, the browser will prompt the user for basic auth credentials. I tried a few approaches for fixing this, but in the end it was easiest and safest to send a 403 status instead.

@rlucioni please review