GenericPLEG's 1s relist() loop races against pod network setup.  It
may be called after the infra container has started but before
network setup is done, since PLEG and the runtime's SyncPod() run
in different goroutines.

Track network setup status and don't bother trying to read the pod's
IP address if networking is not yet ready.

See also: https://bugzilla.redhat.com/show_bug.cgi?id=1434950

Mar 22 12:18:17 ip-172-31-43-89 atomic-openshift-node: E0322
   12:18:17.651013   25624 docker_manager.go:378] NetworkPlugin
   cni failed on the status hook for pod 'pausepods22' - Unexpected
   command output Device "eth0" does not exist.