found a redundant code (stdlib.h already defines the NULL macro)


commit e33747a4b1a45acdd696a4e07bbd40ea7fb37366
Author: Stefan Krah <skrah@bytereef.org>
Date:   Thu Nov 22 22:49:11 2012 +0100

    Issue #13057: Include stdio.h when NULL is used in configure.ac.
    
    --HG--
    branch : 3.3

diff --git a/configure b/configure
index 4a861ed..534c8df 100755
--- a/configure
+++ b/configure

...

@@ -14833,6 +14834,7 @@ else
   cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
 
+#include <stdio.h>
 #include<stdlib.h>
 int main() {
     size_t len = -1;