manager: include config-validator.hpp always

There was an issue with

phosphor::led::validateConfigV1(systemLedMap);

being not included when using meson option

use-json

as false (yaml config), since it was transitively included
by manager/json-parser.hpp

Directly including it should fix the issue.

Change-Id: I056cd524ff255e4409844f74bd7755ab5ee857d6
Signed-off-by: Alexander Hansen <alexander.hansen@9elements.com>
diff --git a/manager/config-validator.hpp b/manager/config-validator.hpp
index 5d9ff5f..1dd6029 100644
--- a/manager/config-validator.hpp
+++ b/manager/config-validator.hpp
@@ -1,3 +1,5 @@
+#pragma once
+
 #include "grouplayout.hpp"
 #include "ledlayout.hpp"