libx264: fix open gop default.

Please use -x264opts to force open gop
This fixes Ticket268
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

libavcodec/libx264.c

@@ -377,7 +377,7 @@ 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;