rework metadata

Signed-off-by: Vasiliy Tolstov <v.tolstov@unistack.org>

server/noop.go

@@ -112,8 +112,8 @@ func (n *noopServer) Register() error {
 	}
 	n.RUnlock()
 
-	service.Nodes[0].Metadata["protocol"] = "noop"
-	service.Nodes[0].Metadata["transport"] = service.Nodes[0].Metadata["protocol"]
+	service.Nodes[0].Metadata.Set("protocol", "noop")
+	service.Nodes[0].Metadata.Set("transport", "noop")
 	service.Endpoints = endpoints
 
 	n.RLock()

server/registry.go

@@ -77,8 +77,8 @@ func NewRegisterService(s Server) (*register.Service, error) {
 	}
 	node.Metadata = metadata.Copy(opts.Metadata)
 
-	node.Metadata["server"] = s.String()
-	node.Metadata["register"] = opts.Register.String()
+	node.Metadata.Set("server", s.String())
+	node.Metadata.Set("register", opts.Register.String())
 
 	return &register.Service{
 		Name:     opts.Name,