fix wrong AVPlayer.mediaStopPosition. issue 322

fix wrong AVPlayer.mediaStopPosition. issue 322 commit
31b150eb2a7e2a4cd3bc638ec0ec2d66144c737d
seek error if media start time >0   commit
d91dccac13902f7f034feb97d2363b405a7a93aa 1 parent 31b150e of
upstreammaster
WangBin wang-bin authored 5 hours ago
of upstreammaster