Fix NAT helper code to update TCP window tracking information
if it resizes payload (and thus alrers sequence numbers).

This patchlet was somehow lost during 2.4.x->2.6.x port of TCP 
window tracking :(

Signed-off-by: Harald Welte <laforge@netfilter.org>

--- linux-2.6.9-rc3-plain/net/ipv4/netfilter/ip_nat_helper.c	2004-10-01 12:08:40.000000000 +0000
+++ linux-2.6.9-rc3-test/net/ipv4/netfilter/ip_nat_helper.c	2004-10-01 13:37:05.283639640 +0000
@@ -347,7 +347,7 @@
 	return 1;
 }
 
-/* TCP sequence number adjustment.  Returns true or false.  */
+/* TCP sequence number adjustment.  Returns 1 on success, 0 on failure */
 int
 ip_nat_seq_adjust(struct sk_buff **pskb, 
 		  struct ip_conntrack *ct, 
@@ -396,7 +396,12 @@
 	tcph->seq = newseq;
 	tcph->ack_seq = newack;
 
-	return ip_nat_sack_adjust(pskb, tcph, ct, ctinfo);
+	if (!ip_nat_sack_adjust(pskb, tcph, ct, ctinfo))
+		return 0;
+
+	ip_conntrack_tcp_update(*pskb, ct, dir);
+
+	return 1;
 }
 
 static inline int