xmlrpc: fix compiler warning #612

> CC (gcc) [M xmlrpc.so]		xmlrpc.o
> In file included from /usr/include/strings.h:26:0,
>                  from xmlrpc.c:28:
> /usr/include/features.h:148:3: warning: #warning "_BSD_SOURCE and _SVID_SOURCE are deprecated, use _DEFAULT_SOURCE" [-Wcpp]
>  # warning "_BSD_SOURCE and _SVID_SOURCE are deprecated, use _DEFAULT_SOURCE"

modules/xmlrpc/xmlrpc.c

@@ -24,6 +24,7 @@
 #endif
 #define _XOPEN_SOURCE_EXTENDED 1  /* solaris */
 #define _SVID_SOURCE 1            /* timegm */
+#define _DEFAULT_SOURCE 1         /* _SVID_SOURCE is deprecated */
 
 #include <strings.h>
 #include <time.h>