d/control: bump std-version to 4.4.0

No changes required per policy upgrade checklist.
Signed-off-by: Arturo Borrero Gonzalez <arturo@debian.org>

debian/control

@@ -15,7 +15,7 @@ Build-Depends: autoconf,
                libnfnetlink-dev,
                libnftnl-dev (>= 1.1.3),
                libtool (>= 2.2.6)
-Standards-Version: 4.3.0
+Standards-Version: 4.4.0
 Homepage: http://www.netfilter.org/
 Vcs-Git: https://salsa.debian.org/pkg-netfilter-team/pkg-iptables
 Vcs-Browser: https://salsa.debian.org/pkg-netfilter-team/pkg-iptables