SSO and e-mail addresses having a plus sign

[david (David Taylor)]

A little late, I know. But in case anyone else runs into this problem.

@thabbs

Following Official Single-Sign-On for Discourse (sso) I must not urlencode the payload before encoding it to base64

In fact we should urlencode the payload before base64 encoding. Our wordpress plugin and our ruby implementation both use library functions to build the payload, which automatically takes care of the encoding.

I updated the docs to make it more explicit:

@sam

3. Create a new url-encoded payload