Eliminate gratuitous DB difference vs Nova
Eliminate gratuitous DB difference vs Nova

Looks like this was an abritrary cleanup done as part of the import. It
conflicts with a more recent change in Nova.

We can move to using try_import() once we've killed the Nova copy
of this code.

Change-Id: I5c67d3fbd846a262feb724e26b14447a76561ae6

openstack/oslo.db,vikt0rs/oslo.db,JioCloud/oslo.db,varunarya10/oslo.db,akash1808/oslo.db,malor/oslo.db,magic0704/oslo.db,openstack/oslo.db