Incorrect error if user exists on sign up form

[enilsen16]

If the user already exists, but tries to sign up again using the original email but a different password, rather than prompt the user that the email already exists, the error returned is password_does_not_match. This is because technically users can log in via the sign up form.

[charleshan]

+1. Temporary solution:

# mix.exs

depf deps do
  [
    {:ueberauth_facebook, git: "https://github.com/ueberauth/ueberauth_facebook.git", ref: "2e3c118"}
  ]
end