[Bug] Mismatch path for read/write to pre-authorized config

[elinep]

Streamlit Version

1.45.1

Streamlit Authenticator Version

0.4.2

Environment

ubuntu, python3.12

What happened?

The pre_authorized feature works only once.

What did you expect to happen?

I expect to be able to register multiple times when using pre_authorised email list.

Steps to reproduce

Context:

• Pass a authenticator config as a path
• Use pre-authorized email list for registration

When using a config to allow only certain emails to register, register_user function expects the following format for the config:

pre-authorised:
  emails:
     - foo@mail.com
     -  ...

Once a user registers successfully, register_user function remove the email from the list and updates the config file but changes its structure:

pre-authorised:
     - foo@mail.com

Next registration attempts will crash.

The relevant piece of code :

        if not pre_authorized and self.path:
            # HERE we  read from pre-authorized.emails
            pre_authorized = self.config.get('pre-authorized', {}).get('emails', None)
        if isinstance(pre_authorized, list):
            if new_email in pre_authorized:
                self._register_credentials(new_username, new_first_name, new_last_name,
                                           new_password, new_email, password_hint, roles)
                pre_authorized.remove(new_email)
                if self.path:
                    # HERE we write back the email list to pre-authorized instead of authorized.emails
                    Helpers.update_config_file(self.path, 'pre-authorized', pre_authorized)