NSD logging control connection when using a filesystem socket

Hi NSD developers,

I'm using the new filesystem socket feature of NSD 4.1.24 to control it,
and I've noticed this in the log:

[2018-08-13 12:55:37.861] nsd[26856]: info: new control connection from
0.0.0.0
[2018-08-13 12:55:37.862] nsd[26856]: info: control cmd:  transfer
[2018-08-13 12:56:39.501] nsd[26856]: info: new control connection from
0.0.1.0
[2018-08-13 12:56:39.501] nsd[26856]: info: control cmd:  status
[2018-08-13 13:00:15.481] nsd[26856]: info: new control connection from
0.0.1.0
[2018-08-13 13:00:15.481] nsd[26856]: info: control cmd:  transfer
[2018-08-13 13:00:19.921] nsd[26856]: info: new control connection from
19.0.0.0
[2018-08-13 13:00:19.921] nsd[26856]: info: control cmd:  status

Notice the "new control connection from ..." lines. They look like IP
addresses, and they're not consistent (0.0.0.0, 0.0.1.0, 19.0.0.0). Is
this a bug?

Anand