When debug is enabled, also use nsupdate's debug logging
so that the user can see potential issues with the nsupdate
transaction.
Signed-off-by: Daniel F. Dickinson <cshored@thecshore.com>
on Ubuntu 14.04.1 LTS if nsupdate runs without port number given it treated argument following server name as port number.
and throws error:
```
port 'update' is not numeric
syntax error
```