Since the user is already in the browser, put the error message in the
browser with a message to log out and then log in as the right user.
Issue #5895
Requires https://github.com/owncloud/oauth2/pull/45
This commit moves the reply after we got the token reply from
the server, that allows to reply with an error to the browser
if the login does not work.
- Add category to the all messages (they did not have it was merged right after
the patch to add category everywhere, but this code did not have it.)
- Make sure there is no warnings in the normal flow. (The wizard does a request
without authentication to determine the auth type)
