backport change from the iaxclient sf repository rev 558

git-svn-id: http://svn.freeswitch.org/svn/freeswitch/trunk@5151 d0543943-73ff-0310-b7d9-9358b9ac24b2

libs/iax/src/md5.h

 #ifndef MD5_H
 #define MD5_H
 
-#ifdef __alpha
+#ifdef __alpha || defined(__x86_64)
 typedef unsigned int uint32;
 #else
 typedef unsigned long uint32;