The old statement returned `None` for such a `password_config` (like the one
created on first run), thus retrieval of the `pepper` key failed with
`AttributeError`.

Fixes #5315

Signed-off-by: Ivan Vilata i Balaguer <ivan@selidor.net>

* port hash_password

* changelog

Signed-off-by: Kent Shikama <kent@kentshikama.com>

Replace the bash/perl gen_password script with a python one, and write a note
on how to use it.