bug fix - no prefix when the moov is very small
bug fix - no prefix when the moov is very small

smaller than the initial read size

kaltura/nginx-vod-module,kaltura/nginx-vod-module,kaltura/nginx-vod-module,kaltura/nginx-vod-module,doublex/nginx-vod-module,kaltura/nginx-vod-module,doublex/nginx-vod-module,doublex/nginx-vod-module,kaltura/nginx-vod-module,doublex/nginx-vod-module,doublex/nginx-vod-module,doublex/nginx-vod-module