Merge pull request #138 from srid/handle-port-mapper-error

handle errors during the creation of port mapper

network.go

@@ -349,6 +349,9 @@ func newNetworkManager(bridgeIface string) (*NetworkManager, error) {
 	}
 
 	portMapper, err := newPortMapper()
+	if err != nil {
+		return nil, err
+	}
 
 	manager := &NetworkManager{
 		bridgeIface:   bridgeIface,