endure that puppdb is a hash

functions/fw_builder.pp

@@ -60,9 +60,11 @@ function fw_builder::fw_builder() {
       # querying 'puppetDB', if 'puppetdb' is defined
       #
       if ($fw_conf['custom_ipset'][$name]['puppetdb']) {
+        $pdb_hash = $fw_conf['custom_ipset'][$name]['puppetdb']
+        if $pdb_hash !~ Hash { fail("${pdb_hash} must be a hash") }
         # check if "env" was defined and it contains proper values
         $pdb_filter = join(
-          $fw_conf['custom_ipset'][$name]['puppetdb'].map |$hash| {
+          $pdb_hash.map |$hash| {
             if $hash['env'] {
               # wrong setting for "env" creates an empty fact and breaks puppet on the host
               if $hash['env'] !~ Fw_builder::Puppet_environment {