使用.net的通信组件，创建客户端登录不成功

需要在初始化 AVRealtime 之前先初始化 AVClient，参考代码如下：

            var appId = "xxx";
            var appKey = "yyy";
            var server = "https://zzz.lc-cn-n1-shared.com";
            AVClient.Initialize(appId, appKey, server);
            var realtime = new AVRealtime(new AVRealtime.Configuration {
                ApplicationId = appId,
                ApplicationKey = appKey
            });