Config: Outbound proxy config no need to be nested (#5124)

Like https://github.com/XTLS/Xray-core/commit/eda8be601f56c788b1ad176c7d68d8e2ce22c7ca

infra/conf/vmess_test.go

@@ -58,6 +58,40 @@ func TestVMessOutbound(t *testing.T) {
 				},
 			},
 		},
+		{
+			Input: `{
+				"address": "127.0.0.1",
+				"port": 80,
+				"id": "e641f5ad-9397-41e3-bf1a-e8740dfed019",
+				"email": "love@example.com",
+				"level": 255
+			}`,
+			Parser: loadJSON(creator),
+			Output: &outbound.Config{
+				Receiver: []*protocol.ServerEndpoint{
+					{
+						Address: &net.IPOrDomain{
+							Address: &net.IPOrDomain_Ip{
+								Ip: []byte{127, 0, 0, 1},
+							},
+						},
+						Port: 80,
+						User: []*protocol.User{
+							{
+								Email: "love@example.com",
+								Level: 255,
+								Account: serial.ToTypedMessage(&vmess.Account{
+									Id: "e641f5ad-9397-41e3-bf1a-e8740dfed019",
+									SecuritySettings: &protocol.SecurityConfig{
+										Type: protocol.SecurityType_AUTO,
+									},
+								}),
+							},
+						},
+					},
+				},
+			},
+		},
 	})
 }