Issue 48864 - Fix FreeIPA build

Bug Description:
FreeIPA build fails because of incorrect include files

https://pagure.io/389-ds-base/issue/48864

Reviewed by: mreynolds (Thanks!)

ldap/servers/slapd/slapi-plugin.h

@@ -28,7 +28,7 @@ extern "C" {
 #endif
 
 /* Provides our int types and platform specific requirements. */
-#include <slapi_pal.h>
+#include "slapi_pal.h"
 
 #include "prtypes.h"
 #include "ldap.h"

ldap/servers/slapd/slapi_pal.h

@@ -19,7 +19,9 @@
 
 #pragma once
 
+#ifdef HAVE_CONFIG_H
 #include <config.h>
+#endif
 
 #ifdef HAVE_INTTYPES_H
 #include <inttypes.h>