ship current version of `ldap_auth_provider.py`

Hey.

Unfortunately I have to use *buntu for some Matrix server which I need to set up at some large research centre, for which - unlike as for Debian - no current/maintained packages are available, which is why I use the upstream packages you provide.

But it turns out, that the version of https://github.com/matrix-org/matrix-synapse-ldap3/ you ship with that, is a bit outdated.

In particular, it lacks https://github.com/matrix-org/matrix-synapse-ldap3/commit/bc90bde8f808039fa05366cb023f5c682c3d0bbc which allows a filter (e.g. to check whether a user is part of a group) to be used without at bind DN / passphrase.

Could you possibly consider to upgrade that shipped version?

I can of course just install the current one manually, but that makes it quite likely to get overwritten on the next package upgrade and me forgetting to replace it again.

And then it doesn't just fail, but simply not enforce the additional group membership filter anymore.

Thanks,
Chris.