feat(webclient): add new query_online function

There may be a loss of performance
Therefore, it is not enabled by default

http/controller/web/index.go

@@ -3,6 +3,7 @@ package web
 import (
 	"Gwen/global"
 	"github.com/gin-gonic/gin"
+	"strconv"
 )
 
 type Index struct {
@@ -14,11 +15,13 @@ func (i *Index) Index(c *gin.Context) {
 
 func (i *Index) ConfigJs(c *gin.Context) {
 	apiServer := global.Config.Rustdesk.ApiServer
-
+	magicQueryonline := strconv.Itoa(global.Config.Rustdesk.WebclientMagicQueryonline)
 	tmp := `
 localStorage.setItem('api-server', "` + apiServer + `")
 const ws2_prefix = 'wc-'
 localStorage.setItem(ws2_prefix+'api-server', "` + apiServer + `")
-`
+
+window.webclient_magic_queryonline = ` + magicQueryonline + ``
+
 	c.String(200, tmp)
 }