Fix for endianness (bug #1174)

git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@2363 65c4cc65-6c06-0410-ace0-fbb531ad65f3

md5.c

 /* MD5 checksum routines used for authentication.  Not covered by GPL, but
    in the public domain as per the copyright below */
-
+#include <endian.h>
 # if __BYTE_ORDER == __BIG_ENDIAN || BYTE_ORDER == BIG_ENDIAN
 #  define HIGHFIRST 1
 # endif