macs header files are a bit weird.

git-svn-id: http://svn.freeswitch.org/svn/freeswitch/trunk@5173 d0543943-73ff-0310-b7d9-9358b9ac24b2

src/include/switch.h

@@ -51,7 +51,9 @@
 #define FREESWITCH_OID_PREFIX ".1.3.6.1.4.1." FREESWITCH_PEN
 #define FREESWITCH_ITAD "543"
 #define __EXTENSIONS__ 1
+#ifndef MACOSX
 #define _XOPEN_SOURCE 600
+#endif
 #include <stdlib.h>
 #include <stdio.h>
 #include <stdarg.h>