libyang CHANGE headers includes cleanup using include-what-you-use tool (#1098)

diff --git a/tools/lint/main_ni.c b/tools/lint/main_ni.c
index 67bd6ae..8da6a87 100644
--- a/tools/lint/main_ni.c
+++ b/tools/lint/main_ni.c
@@ -12,7 +12,7 @@
  *     https://opensource.org/licenses/BSD-3-Clause
  */
 
-#include "config.h"
+#define _GNU_SOURCE
 
 #include <stdio.h>
 #include <stdlib.h>
@@ -25,9 +25,13 @@
 #include <string.h>
 #include <unistd.h>
 
-#include "commands.h"
 #include "libyang.h"
 
+#include "tools/config.h"
+
+#include "commands.h"
+
+
 volatile uint8_t verbose = 0;
 
 #if 0