Always use a default network if no other networks are set.
Always use a default network if no other networks are set.

also add network labels.

Signed-off-by: Daniel Nephin <6347c07ae509164cffebfb1e2a0d6ed64958db19@docker.com>

cpuguy83/cli,Zebrilee/cli,redpanda/cli,thaJeztah/cli,docker/cli,ashfall/cli,Zebrilee/cli,ashfall/cli,riyazdf/cli,docker/cli,dnephin/cli,riyazdf/cli,allencloud/cli,redpanda/cli,e11137/cli,allencloud/cli,e11137/cli,gdevillele/cli,thaJeztah/cli,cpuguy83/cli,dnephin/cli