Rebuild pulls in updates to layer-ovn which enables use
of Netplan to configure SR-IOV and Hardware Offload.
Also drop past release specific classes. As part of the migration
to charmhub we have also changed the release strategy from having
every release support all previous supported os/release
combinations to only support current and previous version (to
ensure N+1 upgrades).
Change-Id: Iaccd569a6d8f1e46b13f34428eb0a5c12daa1602
Frode Nordahl
b4644b6ade