Replace unnecessary DISABLE_ZLIB define in pgcrypto with HAVE_LIBZ from core.

Patch from Marko Kreen.

contrib/pgcrypto/Makefile

@@ -1,5 +1,5 @@
 #
-# $PostgreSQL: pgsql/contrib/pgcrypto/Makefile,v 1.24 2006/07/13 04:15:24 neilc Exp $
+# $PostgreSQL: pgsql/contrib/pgcrypto/Makefile,v 1.25 2007/01/14 20:55:14 alvherre Exp $
 #
 
 INT_SRCS = md5.c sha1.c sha2.c internal.c internal-sha2.c blf.c rijndael.c \
@@ -9,17 +9,13 @@ INT_TESTS = sha2
 OSSL_SRCS = openssl.c pgp-mpi-openssl.c
 OSSL_TESTS = sha2 des 3des cast5
 
-ZLIB_OFF_CFLAGS = -DDISABLE_ZLIB
 ZLIB_TST = pgp-compression
 ZLIB_OFF_TST = pgp-zlib-DISABLED
 
 CF_SRCS = $(if $(subst no,,$(with_openssl)), $(OSSL_SRCS), $(INT_SRCS))
 CF_TESTS = $(if $(subst no,,$(with_openssl)), $(OSSL_TESTS), $(INT_TESTS))
-CF_CFLAGS = $(if $(subst yes,,$(with_zlib)), $(ZLIB_OFF_CFLAGS))
 CF_PGP_TESTS = $(if $(subst no,,$(with_zlib)), $(ZLIB_TST), $(ZLIB_OFF_TST))
 
-PG_CPPFLAGS	= $(CF_CFLAGS)
-
 SRCS		= pgcrypto.c px.c px-hmac.c px-crypt.c \
 		crypt-gensalt.c crypt-blowfish.c crypt-des.c \
 		crypt-md5.c $(CF_SRCS) \

contrib/pgcrypto/pgp-compress.c

@@ -26,7 +26,7 @@
  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  *
- * $PostgreSQL: pgsql/contrib/pgcrypto/pgp-compress.c,v 1.5 2005/10/15 02:49:06 momjian Exp $
+ * $PostgreSQL: pgsql/contrib/pgcrypto/pgp-compress.c,v 1.6 2007/01/14 20:55:14 alvherre Exp $
  */
 
 #include "postgres.h"
@@ -40,7 +40,7 @@
  * Compressed pkt writer
  */
 
-#ifndef DISABLE_ZLIB
+#ifdef HAVE_LIBZ
 
 #include <zlib.h>
 
@@ -312,7 +312,8 @@ pgp_decompress_filter(PullFilter ** res, PGP_Context * ctx, PullFilter * src)
 {
 	return pullf_create(res, &decompress_filter, ctx, src);
 }
-#else							/* DISABLE_ZLIB */
+
+#else							/* !HAVE_ZLIB */
 
 int
 pgp_compress_filter(PushFilter ** res, PGP_Context * ctx, PushFilter * dst)