Fix undeclared variable

cmd/permissioning.go

@@ -39,7 +39,7 @@ func (m *RegistrationImpl) RegisterNode(ID []byte, ServerAddr, ServerTlsCert,
 		return errors.Errorf(
 			"Node with registration code %+v has already been registered", RegistrationCode)
 	}
-
+	pk := &m.State.GetPrivateKey().PrivateKey
 	// Load the node and gateway certs
 	nodeCertificate, err := tls.LoadCertificate(ServerTlsCert)
 	if err != nil {