changed MPGA_PACKET_SIZE to 1024

we can't operate with 4 KB blocks since with low bitrate MP3 streams
we'll  end up putting too many PCRs into one block.

modules/demux/mpeg/mpga.c

@@ -32,7 +32,7 @@
 #include "vlc_codec.h"
 #include "vlc_meta.h"
 
-#define MPGA_PACKET_SIZE 4096
+#define MPGA_PACKET_SIZE 1024
 
 /*****************************************************************************
  * Module descriptor