Log Message:
py-ldap: updated to 3.4.0

Released 3.4.0 2021-11-26

This release requires Python 3.6 or above,
and is tested with Python 3.6 to 3.10.
Python 2 is no longer supported.

New code in the python-ldap project is available under the MIT licence
(available in ``LICENCE.MIT`` in the source). Several contributors have agreed
to apply this licence their previous contributions as well.
See the ``README`` for details.

The following undocumented functions are deprecated and scheduled for removal:
- ``ldap.cidict.strlist_intersection``
- ``ldap.cidict.strlist_minus``
- ``ldap.cidict.strlist_union``

Security fixes:
* Fix inefficient regular expression which allows denial-of-service attacks
  when parsing specially-crafted LDAP schema.
  (GHSL-2021-117)

Changes:
* On MacOS, remove option to make LDAP connections from a file descriptor
  when built with the system libldap (which lacks the underlying function,
  ``ldap_init_fd``)
* Attribute values of the post read control are now ``bytes``
  instead of ISO8859-1 decoded ``str``
* ``LDAPUrl`` now treats urlscheme as case-insensitive
* Several OpenLDAP options are now supported:
  * ``OPT_X_TLS_REQUIRE_SAN``
  * ``OPT_X_SASL_SSF_EXTERNAL``
  * ``OPT_X_TLS_PEERCERT``

Fixes:
* The ``copy()`` method of ``cidict`` was added back. It was unintentionally
  removed in 3.3.0
* Fixed getting/setting ``SASL`` options on big endian platforms
* Unknown LDAP result code are now converted to ``LDAPexception``,
  rather than raising a ``SystemError``.

slapdtest:
* Show stderr of slapd -Ttest
* ``SlapdObject`` uses directory-based configuration of ``slapd``
* ``SlapdObject`` startup is now faster

Infrastructure:
* CI now runs on GitHub Actions rather than Travis CI.