[gnome-nettool] Add missing header to make this compile on OpenBSD (and others too perhaps)

[Jasper Lievisse Adriaanse <jasperla src gnome org>]

commit bf26bf3996d2947feedfaa8cd8eecaa2809c0aa1
Author: Jasper Lievisse Adriaanse <jasper humppa nl>
Date:   Wed Jun 15 10:33:26 2011 +0200

    Add missing header to make this compile on OpenBSD (and others too perhaps)

 src/lookup.c |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)
---
diff --git a/src/lookup.c b/src/lookup.c
index 1a9c1fb..9592e6a 100644
--- a/src/lookup.c
+++ b/src/lookup.c
@@ -21,6 +21,7 @@
 #include <gtk/gtk.h>
 #include <glib/gi18n.h>
 #include <glib/gprintf.h>
+#include <sys/types.h>
 
 #include "lookup.h"
 #include "utils.h"