remove unused code

proxy/vmess/protocol/testing/static_userset.go

@@ -1,20 +0,0 @@
-package mocks
-
-import (
-	"github.com/v2ray/v2ray-core/common/protocol"
-	"github.com/v2ray/v2ray-core/common/uuid"
-)
-
-type StaticUserSet struct {
-}
-
-func (us *StaticUserSet) Add(user *protocol.User) error {
-	return nil
-}
-
-func (us *StaticUserSet) Get(userhash []byte) (*protocol.User, protocol.Timestamp, bool) {
-	id, _ := uuid.ParseString("703e9102-eb57-499c-8b59-faf4f371bb21")
-	return &protocol.User{
-		ID: protocol.NewID(id),
-	}, 0, true
-}