Fix the eddsa system test to allow parallel run

The eddsa test was not adapted to dynamic ports, so we had to run it in
sequence.  This commit adds support for dynamic ports, and also makes
all the scripts shellcheck clean.

bin/tests/system/eddsa/ns2/named.conf.in

@@ -0,0 +1,34 @@
+/*
+ * Copyright (C) Internet Systems Consortium, Inc. ("ISC")
+ *
+ * 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 http://mozilla.org/MPL/2.0/.
+ *
+ * See the COPYRIGHT file distributed with this work for additional
+ * information regarding copyright ownership.
+ */
+
+// NS2
+
+controls { /* empty */ };
+
+options {
+	query-source address 10.53.0.2;
+	notify-source 10.53.0.2;
+	transfer-source 10.53.0.2;
+	port @PORT@;
+	pid-file "named.pid";
+	listen-on { 10.53.0.2; };
+	listen-on-v6 { none; };
+	recursion yes;
+	notify yes;
+	dnssec-validation yes;
+};
+
+zone "." {
+	type hint;
+	file "../../common/root.hint";
+};
+
+include "trusted.conf";