[Samba] Bind 9.12.x support status

[Taner Tas]

> Nobody has looked into it yet.  Likely just an extra build rule
> required, I would need to see the 9.11 and 9.12 DLZ header files to
> check. 
> 
> Aaron Haslett (CC'ed) may be able to help once he fights past the other
> BIND9 issues he is looking at. 
> 
> Andrew Bartlett

Thanks for response. I actually looked it myself. Since there is no
DLZ ABI changes since 9.11, I reckon as it would be easy as making 
"python/samba/provision/sambadns.py" aware of Bind 9.12 will do the
job without any hassle.

Any extra build routine for 9.12 will do things complicated 
without a sensible reason. I prepared a patch and tested it locally.
It seems it just works fine during provision and as a dns backend.

Patch attached.

Regards.

-- 
Taner Tas <taner76 at gmail.com>