Update notrack rules

Update notrack rules

* switch from NOTRACK to CT target (deprecated around 2012)
* add output accept for sport 53
* describe firewalld configuration for newer centos/fedora/redhat versions

```
Date: Thu, 20 Dec 2012 12:26:22 +0100
Subject: [PATCH] netfilter: xt_CT: recover NOTRACK target support

Florian Westphal reported that the removal of the NOTRACK target
(9655050 netfilter: remove xt_NOTRACK) is breaking some existing
setups.

That removal was scheduled for removal since long time ago as
described in Documentation/feature-removal-schedule.txt
```

https://patchwork.ozlabs.org/patch/207653/