avcodec: set rc-buffer-size to 0, as it is default in ffmpeg/avconv

(cherry picked from commit 1d981d16b744b000414cd5a2cc38db90d26d3903)
Signed-off-by: Jean-Baptiste Kempf <jb@videolan.org>

modules/codec/avcodec/avcodec.c

@@ -163,7 +163,7 @@ vlc_module_begin ()
                  ENC_VT_LONGTEXT, true )
     add_bool( ENC_CFG_PREFIX "pre-me", false, ENC_PRE_ME_TEXT,
               ENC_PRE_ME_LONGTEXT, true )
-    add_integer( ENC_CFG_PREFIX "rc-buffer-size", 224*1024*8,
+    add_integer( ENC_CFG_PREFIX "rc-buffer-size", 0,
                  ENC_RC_BUF_TEXT, ENC_RC_BUF_LONGTEXT, true )
     add_float( ENC_CFG_PREFIX "rc-buffer-aggressivity", 1.0,
                ENC_RC_BUF_AGGR_TEXT, ENC_RC_BUF_AGGR_LONGTEXT, true )