Thanks for fixing @zogstrip. I noticed the social buttons in sign ups were not responding to the click action and my fix resulted in the login buttons being broken. Moral of the story is to not make typos 
I should have read the docs clearly before merging because setting to ‘none’ by default clearly said
it will return an error if the user is not already authenticated and has not pre-configured consent for the requested scopes.
Anyway, I’ve reintroduce the site settings in
https://github.com/discourse/discourse/commit/24d0a7a4c71ba5147a5741c7a19dd061296098a0