added missing config.h includes for extended LFS support

All sources which might work with large files must include config.h,
to get Large File Support on 32 bit platforms.

src/fd_util.c

@@ -26,8 +26,8 @@
  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
+#include "config.h" /* must be first for large file support */
 #include "fd_util.h"
-#include "config.h"
 
 #if !defined(_GNU_SOURCE) && (defined(HAVE_PIPE2) || defined(HAVE_ACCEPT4))
 #define _GNU_SOURCE