Use fixed date/time (the time choosen was the time the import was done on

-HEAD) in libntp so we can make reproducible build.

PR:		bin/201661
Reviewed by:	gjb, cy, roberto
MFC after:	3 days
Differential Revision:	https://reviews.freebsd.org/D3122

usr.sbin/ntp/config.h

@@ -1782,3 +1782,8 @@ typedef union mpinfou {
 	# endif
 	#endif	/* !defined(_KERNEL) && !defined(PARSESTREAM) */
 	
+/*
+ * FreeBSD specific: Explicitly specify date/time for reproducible build.
+ */
+#define	MKREPRO_DATE "Jul 04 2015"
+#define	MKREPRO_TIME "15:42:16"