fix Hash signature

manifests/config_file.pp

@@ -5,7 +5,7 @@ class secure_afs_request::config_file (
   Optional[String]          $test_address   = undef,
   String                    $db_config_file = '/etc/secure-afs-request/database.ini',
   String                    $from_address   = 'afs-request@stanford.edu',
-  Hash[String]              $remctl_servers = {},
+  Hash[String, String]      $remctl_servers = {},
 ) {
 
   # Make sure the configuration directory exists (or not).