No auto provisioning of a PTR for IPv6

```
What steps will reproduce the problem?
1. Create an AAAA record

What is the expected output? What do you see instead?
Both AAAA and PTR records are created


What version of the product are you using? On what operating system?
Official demo http://pdnsdemo.neosolve.de/


```

Original issue reported on code.google.com by `unix....@gmail.com` on 13 Dec 2011 at 3:24
