Remove quota "ConfDriver", deprecated in Liberty

[Rodolfo Alonso]

Remove quota "ConfDriver" code because it was deprecated in Liberty.

[Rodolfo Alonso (rodolfo-alonso-hernandez)]

Related patch: https://review.opendev.org/c/openstack/networking-bgpvpn/+/790972

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.opendev.org/c/openstack/neutron/+/790999

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.opendev.org/c/openstack/neutron/+/790999
Committed: https://opendev.org/openstack/neutron/commit/ad31c58d60142cffcdea86d0257dc10277b53ff0
Submitter: "Zuul (22348)"
Branch: master

commit ad31c58d60142cffcdea86d0257dc10277b53ff0
Author: Rodolfo Alonso Hernandez <email address hidden>
Date: Wed May 12 13:28:36 2021 +0000

    Remove ``ConfDriver`` code

    The quota driver ``ConfDriver`` was deprecated in Liberty release.

    ``NullQuotaDriver`` is created for testing although it could be used
    in production if no quota enforcement is needed. However, because
    the Quota engine is not plugable (is an extension always loaded), it
    could be interesting to make it plugable as any other plugin.

    This patch also creates a Quota engine driver API class that should be
    used in any Quota engine driver. Currently it is used in the three
    in-tree drivers implemented: ``NullQuotaDriver``, ``DbQuotaDriver``
    and ``DbQuotaNoLockDriver``.

    Change-Id: Ib4af80e18fac52b9f68f26c84a215415e63c2822
    Closes-Bug: #1928211

[OpenStack Infra (hudson-openstack)]

This issue was fixed in the openstack/neutron 19.0.0.0rc1 release candidate.