Add crypto stuff on top of what we already have, rather than replacing!

usr.bin/unzip/Makefile

@@ -1,4 +1,4 @@
-# $NetBSD: Makefile,v 1.4 2017/04/21 23:49:17 christos Exp $
+# $NetBSD: Makefile,v 1.5 2017/04/22 05:32:40 pgoyette Exp $
 
 .include <bsd.own.mk>
 PROG=	unzip
@@ -7,8 +7,8 @@ DPADD+=		${LIBARCHIVE} ${LIBZ} ${LIBBZ2}
 LDADD+=		-larchive -lz -lbz2
 
 .if ${MKCRYPTO:Uno} == "yes"
-LDADD=  -lcrypto
-DPADD=  ${LIBCRYPTO}
+LDADD+=  -lcrypto
+DPADD+=  ${LIBCRYPTO}
 .endif
 
 COPTS.unzip.c += -Wno-format-y2k