控制台打印：
[BoringSSL] nw_protocol_boringssl_get_output_frames(1301) [C1.1:2][0x1023291b0] get output frames failed, state 8196
解决方法：
在application中 的
- (void)applicationWillResignActive:(UIApplication *)application{}
添加
__block UIBackgroundTaskIdentifier bgTask = [[UIApplication sharedApplication] beginBackgroundTaskWithName:@"bg_task" expirationHandler:^{
[[UIApplication sharedApplication] endBackgroundTask:bgTask];
bgTask =UIBackgroundTaskInvalid;
}];
