handle popup in lua instead

data/cdata/ui_scripts/server_list/__init__.lua

@@ -4,3 +4,4 @@ end
 
 require("lobby")
 require("serverlist")
+require("confirm")

data/cdata/ui_scripts/server_list/confirm.lua

@@ -0,0 +1,12 @@
+LUI.MenuBuilder.m_types_build["popup_confirmdownload"] = function()
+    return LUI.MenuBuilder.BuildRegisteredType("generic_yesno_popup", {
+		popup_title = Engine.Localize("@MENU_NOTICE"),
+		message_text = Engine.Localize("@LUA_MENU_3RD_PARTY_CONTENT_DESC", download.getwwwurl()),
+		yes_action = function()
+			download.userdownloadresponse(true)
+		end,
+		no_action = function()
+			download.userdownloadresponse(false)
+		end
+	})
+end