Use prereq.sh for rpzrecurse system test

(cherry picked from commit 0538b7e0da)

bin/tests/system/Makefile.am

@@ -83,14 +83,7 @@ tkey_keydelete_LDADD =		\
 	$(LDADD)		\
 	$(LIBDNS_LIBS)
 
-TESTS =
-
-if HAVE_PERLMOD_NET_DNS
-TESTS +=		\
-	rpzrecurse
-endif HAVE_PERLMOD_NET_DNS
-
-TESTS +=			\
+TESTS =				\
 	acl			\
 	additional		\
 	addzone			\
@@ -168,6 +161,7 @@ TESTS +=			\
 	rootkeysentinel		\
 	rpz			\
 	rpzextra		\
+	rpzrecurse		\
 	rrchecker		\
 	rrl			\
 	rrsetorder		\

bin/tests/system/rpzrecurse/prereq.sh

@@ -0,0 +1,22 @@
+#!/bin/sh
+
+# Copyright (C) Internet Systems Consortium, Inc. ("ISC")
+#
+# SPDX-License-Identifier: MPL-2.0
+#
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0.  If a copy of the MPL was not distributed with this
+# file, you can obtain one at https://mozilla.org/MPL/2.0/.
+#
+# See the COPYRIGHT file distributed with this work for additional
+# information regarding copyright ownership.
+
+. ../conf.sh
+
+if ! ${PERL} -MNet::DNS -e ''
+then
+	echo_i "perl Net::DNS module is required"
+	exit 1
+fi
+
+exit 0

configure.ac

@@ -237,10 +237,6 @@ AC_PATH_PROGS([PERL], [perl5 perl])
 AC_SUBST([PERL])
 AM_CONDITIONAL([HAVE_PERL], [test -n "$PERL"])
 
-AX_PERL_MODULE([Net::DNS])
-AM_CONDITIONAL([HAVE_PERLMOD_NET_DNS],
-	       [test "$HAVE_PERLMOD_NET__DNS" = "yes"])
-
 #
 # Python is optional, it is used only by some of the system test scripts.
 #