[th/no-auto-default-by-ifname]

Currently, if you have a veth device and then we always create a auto-default connection (Wired connection 1) -- unless we already have an existing profile...

In particular, if you delete the "Wired connection 1", then it gets re-created right away. That's because the mechanism to block creating of the auto-default (wired) connection is based on the MAC address (which doesn't work for software devices).

Fix that.