sapenc: Include os_support.h, to provide a fallback definition for socklen_t

Originally committed as revision 25422 to svn://svn.ffmpeg.org/ffmpeg/trunk

libavformat/sapenc.c

@@ -25,6 +25,7 @@
 #include "libavutil/intreadwrite.h"
 #include "internal.h"
 #include "network.h"
+#include "os_support.h"
 #include "rtpenc_chain.h"
 
 struct SAPState {