net/widentd: disable -Werror

On gcc, this warning is given:

widentd.c: In function 'main':
widentd.c:194:3: error: 'memset' used with constant zero length parameter;
  this could be due to transposed parameters
  [-Werror=memset-transposed-args]
   memset(buff, sizeof(buff), 0);
   ^

Removing -Werror is blanket-approved.  This is another port that uses
<bsd.prog.mk> instead of providing an independent makefile, so the
-Werror is coming from the system build framework.

net/widentd/Makefile

@@ -13,6 +13,7 @@ LICENSE=	BSD3CLAUSE
 
 USES=		uidfix tar:xz
 MAKE_ENV+=	BINDIR="${PREFIX}/sbin" MANDIR="${PREFIX}/man/man"
+MAKE_ENV+=	NO_WERROR="defined"
 
 PLIST_FILES=	sbin/widentd man/man8/widentd.8.gz
 USE_RC_SUBR=	widentd