Outbound: One endpoint and at most one user only (#5144)

https://github.com/XTLS/Xray-core/pull/5124#issuecomment-3281091009

Fixes https://github.com/XTLS/Xray-core/pull/5124#pullrequestreview-3218097421

common/protocol/headers.go

@@ -5,7 +5,6 @@ import (
 
 	"github.com/xtls/xray-core/common/bitmask"
 	"github.com/xtls/xray-core/common/net"
-	"github.com/xtls/xray-core/common/uuid"
 	"golang.org/x/sys/cpu"
 )
 
@@ -71,14 +70,6 @@ type ResponseHeader struct {
 	Command ResponseCommand
 }
 
-type CommandSwitchAccount struct {
-	Host     net.Address
-	Port     net.Port
-	ID       uuid.UUID
-	Level    uint32
-	ValidMin byte
-}
-
 var (
 	// Keep in sync with crypto/tls/cipher_suites.go.
 	hasGCMAsmAMD64 = cpu.X86.HasAES && cpu.X86.HasPCLMULQDQ && cpu.X86.HasSSE41 && cpu.X86.HasSSSE3