Don’t generate new accounts if WP Settings “Anyone can register” disabled

If the “Anyone can register” in WordPress’ “Settings > General” is unchecked (so that no users can register by themselves) the plugin should not allow them to bypass this setting, or it should at least give us the option to decide.

Right now, users without an account get an account created when using social login, even if the WordPress “Anyone can register” setting is unchecked.

This means that unwanted users can register into the website through Social Login even if registration is disabled.