models/server: add statistics for proxies enabled privilege mode.

src/frp/models/server/config.go

@@ -297,8 +297,10 @@ func CreateProxy(s *ProxyServer) error {
 			delete(ProxyServers, s.Name)
 		}
 	}
-	s.Init()
 	ProxyServers[s.Name] = s
+	metric.SetProxyInfo(s.Name, s.Type, s.BindAddr, s.UseEncryption, s.UseGzip,
+		s.PrivilegeMode, s.CustomDomains, s.ListenPort)
+	s.Init()
 	return nil
 }