Special case tests for lmdb

When compiling BIND 9 without lmdb, this is promoted from
'not operational' to 'not configured', resulting in a failure (and no
longer a warning) if ldmb-related configuration options are set.

Special case certain system tests to avoid test failures on systems
that do not have lmdb.

bin/tests/system/checkconf/lmdb-mapsize-largest.conf

@@ -0,0 +1,14 @@
+/*
+ * 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.
+ */
+
+options {
+	lmdb-mapsize 1024G;
+};