mod_storage_s3: Remove wrapper and original timestamp from payload (BC) Unpacking the wrapper was already removed in 66986f5271c3 so it was broken already. Just rely on the Last-Modified date instead, it's not going to be accurate if a different timestamp is passed, e.g. with migrations, but that will have to be a future problem. Perhaps the X-Amz-Meta-* can be used?

Generate a DNS UPDATE order in format suitable for `nsupdate` based on
current port configuration.

Example output:

```
$ prosodyctl mod_dnsupdate -d example.com -t xmpp.example.com example.com
zone example.com
server ns1.example.com
ttl 3600
add _xmpp-client._tcp.example.com IN SRV 1 1 5222
add _xmpp-server._tcp.example.com IN SRV 1 1 5269
```