在最新的iOS更新后，对MPMusicPlayerController的setCurrentPlaybackRate调用停止工作，现在出现此错误:2018-04-1516:24:06.904562-0600SampleProject[5659:1836398][SDKPlayback]-[MPMusicPlayerControllersetCurrentPlaybackRate:0.670213]completederror:ErrorDomain=MPCPlayerRequestErrorDomainCode=1"Nocommandsprovided."UserInfo={NSDeb