Include CNI networks in inspect output when not running

We were only including the CNI Network fields in the output of
`podman inspect` when the container was not running. It's simple
enough to fix (populate with empty structs, since we can't fill
anything without a CNI response to get IP address assigned, etc).

This is necessary for Docker compatibility.

Signed-off-by: Matthew Heon <matthew.heon@pm.me>

libpod/networking_linux.go

@@ -828,6 +828,17 @@ func (c *Container) getContainerNetworkInfo() (*define.InspectNetworkSettings, e
 
 	// We can't do more if the network is down.
 	if c.state.NetNS == nil {
+		// We still want to make dummy configurations for each CNI net
+		// the container joined.
+		if len(c.config.Networks) > 0 {
+			settings.Networks = make(map[string]*define.InspectAdditionalNetwork, len(c.config.Networks))
+			for _, net := range c.config.Networks {
+				cniNet := new(define.InspectAdditionalNetwork)
+				cniNet.NetworkID = net
+				settings.Networks[net] = cniNet
+			}
+		}
+
 		return settings, nil
 	}