no easy way to delete a dhcp configuration through the maas-cli

I set up the dhcp configuration using the maas-cli

maas-cli api maas node-group-interfaces new master ip=192.168.21.1 interface=eth0 management=2 subnet_mask=255.255.255.0 broadcast_ip=192.168.21.255 router_ip=192.168.21.1 ip_range_low=192.168.21.10 ip_range_high=192.168.21.50

Then I noticed the interface should have been br0 instead.

I tried a suggestion from Julian to set management to "Unmanaged", management=0

ubuntu@lenovo-RD230-01:~$ maas-cli api maas node-group-interface update master eth0 management=0
200 OK

  Content-Length: 223
    Content-Type: application/json; charset=utf-8
            Date: Tue, 02 Oct 2012 03:33:38 GMT
          Server: Apache/2.2.22 (Ubuntu)
          Status: 200
            Vary: Authorization,Cookie

{
    "ip_range_high": "192.168.21.50",
    "ip_range_low": "192.168.21.10",
    "broadcast_ip": "192.168.21.255",
    "ip": "192.168.21.1",
    "subnet_mask": "255.255.255.0",
    "management": 2,
    "interface": "eth0"
}

I got the 200 OK response but the master node-group-interface still reports as being managed