Include sha1.h from sha.c: It contains several prototypes.

Originally committed as revision 22099 to svn://svn.ffmpeg.org/ffmpeg/trunk

libavutil/sha.c

@@ -25,6 +25,7 @@
 #include "avutil.h"
 #include "bswap.h"
 #include "sha.h"
+#include "sha1.h"
 #include "intreadwrite.h"
 
 /** hash context */