haproxy: Switch to DEBUG_CFLAGS.

The software depends on compiler flags (-fwrapv) for specific overflow
handling, but for some strange reason instead of appending them during
the build regardless of what the user has set CFLAGS to, it allows
CFLAGS to be overridden and aborts at runtime!  Passing in our CFLAGS
via DEBUG_CFLAGS, while not ideal, allows them to be properly combined.

Fix from goekesmi in TritonDataCenter#313.  Bump PKGREVISION.

net/haproxy/Makefile

@@ -1,6 +1,7 @@
-# $NetBSD: Makefile,v 1.83 2021/08/20 05:42:53 adam Exp $
+# $NetBSD: Makefile,v 1.84 2021/08/31 09:17:46 jperkin Exp $
 
 DISTNAME=	haproxy-2.4.3
+PKGREVISION=	1
 CATEGORIES=	net www
 MASTER_SITES=	https://www.haproxy.org/download/${PKGVERSION_NOREV:R}/src/
 
@@ -13,7 +14,7 @@ USE_LANGUAGES=		c
 USE_TOOLS+=		gmake
 BUILD_MAKE_FLAGS+=	ADDLIB=${COMPILER_RPATH_FLAG}${PREFIX}/lib
 BUILD_MAKE_FLAGS+=	CC=${CC:Q}
-BUILD_MAKE_FLAGS+=	CFLAGS=${CFLAGS:Q}
+BUILD_MAKE_FLAGS+=	DEBUG_CFLAGS=${CFLAGS:Q}
 BUILD_MAKE_FLAGS+=	LDFLAGS=${LDFLAGS:Q}
 BUILD_MAKE_FLAGS+=	TARGET=${TARGET}
 BUILD_MAKE_FLAGS+=	USE_REGPARM=1