hls: replace probsize=0 by noheader flag removial.

This fixes h264 timestamps in hls
Fixes ticket1572

Tested-by: crtmpserver
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

libavformat/hls.c

@@ -528,7 +528,8 @@ static int hls_read_header(AVFormatContext *s)
         ret = avformat_open_input(&v->ctx, v->segments[0]->url, in_fmt, NULL);
         if (ret < 0)
             goto fail;
-        v->ctx->probesize = 0;
+
+        v->ctx->ctx_flags &= ~AVFMTCTX_NOHEADER;
         ret = avformat_find_stream_info(v->ctx, NULL);
         if (ret < 0)
             goto fail;