sysutils/unquote: disable date/time nonreproducible build warning

The base system build infrastructure will add -Wdate-time, to avoid
use of nonreproducible __DATE__ and __TIME__ in the base system.

This port makes use of the base system build infrastructure as well as
__DATE__ and/or __TIME__, so explicitly opt out of the warning.

PR:		267902 [exp-run]
Approved by:	jrm
Sponsored by:	The FreeBSD Foundation
Differential Revision:	https://reviews.freebsd.org/D37504

sysutils/unquote/Makefile

@@ -15,5 +15,6 @@ PLIST_FILES=	bin/unquote man/man1/unquote.1.gz
 .if		!defined(NO_RELEASE)
 MAKE_ENV+=	RELEASE=yes
 .endif
+MAKE_ENV+=	NO_WDATE_TIME=yes
 
 .include <bsd.port.mk>