doc: put iptables version into manpage

Signed-off-by: Jan Engelhardt <jengelh@medozas.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
diff --git a/iptables.8.in b/iptables.8.in
index 9947da4..b9d6383 100644
--- a/iptables.8.in
+++ b/iptables.8.in
@@ -1,4 +1,4 @@
-.TH IPTABLES 8 "Jul 03, 2008" "" ""
+.TH IPTABLES 8 "" "@PACKAGE_AND_VERSION@" "@PACKAGE_AND_VERSION@"
 .\"
 .\" Man page written by Herve Eychenne <rv@wallfire.org> (May 1999)
 .\" It is based on ipchains page.