avutil: bump minor version because of av_get_default_channel_layout type fix

Well, probably an ABI breakage at least for 32bit, but hopefully it will go
unnoticed because the fix happened realtively soon.
Signed-off-by: Marton Balint <cus@passwd.hu>
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

libavutil/avutil.h

@@ -40,7 +40,7 @@
 #define AV_VERSION(a, b, c) AV_VERSION_DOT(a, b, c)
 
 #define LIBAVUTIL_VERSION_MAJOR 51
-#define LIBAVUTIL_VERSION_MINOR 19
+#define LIBAVUTIL_VERSION_MINOR 20
 #define LIBAVUTIL_VERSION_MICRO  0
 
 #define LIBAVUTIL_VERSION_INT   AV_VERSION_INT(LIBAVUTIL_VERSION_MAJOR, \