make iptables-restore print the line number in case of an error
(Illes Marci <marci@balabit.hu>)
diff --git a/include/iptables.h b/include/iptables.h
index 858bbdc..205984e 100644
--- a/include/iptables.h
+++ b/include/iptables.h
@@ -106,6 +106,8 @@
 #endif
 };
 
+extern int line;
+
 /* Your shared library should call one of these. */
 extern void register_match(struct iptables_match *me);
 extern void register_target(struct iptables_target *me);