Updated openstack/openstack
Project: openstack/neutron  5a6754181803718c36e2d697b201b87de9078a56

Switch to using of oslo.db

oslo.db first stable release has been cut and we can start using it
instead of openstack/common/db/* code which is now marked obsolete.

Change-Id: I1ccf896922a5a762d37a1a3b93c56c8b8ae8c085