[Bf-webcontent] "don't have a Blender ID yet?" button is broken

[gandalf3]

Clicking the "Don't have a Blender ID yet?" button on 
https://www.blender.org/id/login flips the form around,
but doesn't show the required "First Name" and "Last Name" fields.

The result is that the user enters a username and password, clicks 
submit, then is rejected for not having filled out two previously 
non-existent fields.

Firefox 44.2