Bump version to 1.4.9.1

Signed-off-by: Patrick McHardy <kaber@trash.net>
diff --git a/configure.ac b/configure.ac
index a0a9cda..e9042fb 100644
--- a/configure.ac
+++ b/configure.ac
@@ -1,5 +1,5 @@
 
-AC_INIT([iptables], [1.4.9])
+AC_INIT([iptables], [1.4.9.1])
 
 # See libtool.info "Libtool's versioning system"
 libxtables_vcurrent=5