libx264: fix open GOP

Found-by: relaxed
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

libavcodec/libx264.c

@@ -513,7 +513,7 @@ static av_cold int X264_init(AVCodecContext *avctx)
 
     x4->params.b_interlaced   = avctx->flags & CODEC_FLAG_INTERLACED_DCT;
 
-//    x4->params.b_open_gop     = !(avctx->flags & CODEC_FLAG_CLOSED_GOP);
+    x4->params.b_open_gop     = !(avctx->flags & CODEC_FLAG_CLOSED_GOP);
 
     x4->params.i_slice_count  = avctx->slices;