iOS恢复QQ音乐等播放器中断

在App中如果用AVAudioSession setActive等来中断其它播放器，当自己App中播放完毕，一般要恢复其它播放器。

NSError *err;
[[AVAudioSession sharedInstance] setActive:NO withOptions:AVAudioSessionSetActiveOptionNotifyOthersOnDeactivation error:&err];

setActive:YES与setActive:NO一般要成对出现。

没有setActive:YES然后就setActive:NO会抛异常：

AVAudioSession.mm:623: -[AVAudioSession setActive:withOptions:error:]: Deactivating an audio session that has running I/O. All I/O should be stopped or paused prior to deactivating the audio session.