Do not reassign alias_maps

manifests/files.pp

 class postfix::files {
   include postfix::params
 
+  $alias_maps = $postfix::all_alias_maps
   $inet_interfaces = $postfix::inet_interfaces
   $mail_user = $postfix::mail_user
   $master_smtp = $postfix::master_smtp
@@ -69,7 +70,7 @@ class postfix::files {
 
   ::postfix::config {
     'myorigin':         value => $myorigin;
-    'alias_maps':       value => $postfix::alias_maps;
+    'alias_maps':       value => $alias_maps;
     'inet_interfaces':  value => $inet_interfaces;
   }
 

manifests/init.pp

@@ -124,7 +124,7 @@ class postfix (
     default => $smtp_listen,
   }
 
-  $alias_maps = $ldap ? {
+  $all_alias_maps = $ldap ? {
     false => $alias_maps,
     true  => "\"${alias_maps}, ldap:/etc/postfix/ldap-aliases.cf\"",
   }