Put 'db' parameter back and provide a deprecation warning before remove
Put 'db' parameter back and provide a deprecation warning before remove

The parameter should have been deprecated before its removal to give
callers a chance to adjust their calls to the new argument list.

This patchset follows Ben Nemec's comment in commit
https://review.openstack.org/#/c/569078/

Change-Id: I606796a33f6304276fe78b9868239a0ee5b9f46a

stackforge/osprofiler,openstack/osprofiler,openstack/osprofiler,stackforge/osprofiler,stackforge/osprofiler,openstack/osprofiler