ffmpeg update to june 23 version which fixes mp4 crash on still frames with 3...

source/patched-ffmpeg-mt/libavformat/internal.h

Index: source/patched-ffmpeg-mt/libavformat/internal.h
===================================================================
--- source/patched-ffmpeg-mt/libavformat/internal.h	(revision 50820)
+++ source/patched-ffmpeg-mt/libavformat/internal.h	(working copy)
@@ -131,7 +131,8 @@
  * @param size the size of the str buffer
  * @param proto the protocol identifier, if null, the separator
  *              after the identifier is left out, too
- * @param authorization an optional authorization string, may be null
+ * @param authorization an optional authorization string, may be null.
+ *                      An empty string is treated the same as a null string.
  * @param hostname the host name string
  * @param port the port number, left out from the string if negative
  * @param fmt a generic format string for everything to add after the