resource/location: lint fix: set $server datatype to Optional

Author: kenyon

REFERENCE.md

@@ -1987,7 +1987,7 @@ Default value: `false`
 
 ##### <a name="-nginx--resource--location--server"></a>`server`
 
-Data type: `Variant[String[1], Array[String[1], 1]]`
+Data type: `Optional[Variant[String[1], Array[String[1], 1]]]`
 
 Defines a server or list of servers that include this location
 

manifests/resource/location.pp

@@ -252,7 +252,7 @@
   Enum['present', 'absent'] $ensure                                = 'present',
   Boolean $internal                                                = false,
   String $location                                                 = $name,
-  Variant[String[1], Array[String[1], 1]] $server                  = undef,
+  Optional[Variant[String[1], Array[String[1], 1]]] $server        = undef,
   Optional[String] $www_root                                       = undef,
   Optional[String] $autoindex                                      = undef,
   Optional[Enum['on', 'off']] $autoindex_exact_size                = undef,