Designate returns non-zero Content-Length on some HTTP 204's

It appears that some calls that return an HTTP 204 No Content status, Designate returns a non-zero content-length:

curl -v -X POST http://127.0.0.1:9001/v2/zones/a143f01a-5b1e-4925-a52d-cfa1fe2ac5f9/tasks/abandon
* Hostname was NOT found in DNS cache
* Trying 127.0.0.1...
* Connected to 127.0.0.1 (127.0.0.1) port 9001 (#0)
> POST /v2/zones/a143f01a-5b1e-4925-a52d-cfa1fe2ac5f9/tasks/abandon HTTP/1.1
> User-Agent: curl/7.38.0
> Host: localhost
> Accept: */*
>
< HTTP/1.1 204 No Content
< Content-Length: 2
< X-Openstack-Request-Id: req-fac74a00-e20e-4e15-b6e6-3f1d74167172
< Date: Mon, 13 Jun 2016 19:19:54 GMT
<
* Connection #0 to host localhost left intact

On deletes, this can be a problem:

curl -v -X DELETE localhost/v2/zones/tasks/imports/d335f72d-7149-4777-942a-085cdc591650
* Hostname was NOT found in DNS cache
* Trying ::1...
* connect to ::1 port 80 failed: Connection refused
* Trying 127.0.0.1...
* Connected to localhost (127.0.0.1) port 80 (#0)
> DELETE /v2/zones/tasks/imports/d335f72d-7149-4777-942a-085cdc591650 HTTP/1.1
> User-Agent: curl/7.38.0
> Host: localhost
> Accept: */*
>
< HTTP/1.1 204 No Content
< Content-Length: 2
< X-Openstack-Request-Id: req-daa146a7-4226-426a-a282-630fb7cebd86
< Date: Mon, 13 Jun 2016 20:01:11 GMT
<
* Excess found in a non pipelined read: excess = 2 url = /v2/zones/tasks/imports/d335f72d-7149-4777-942a-085cdc591650 (zero-length body)
* Connection #0 to host localhost left intact

Having a body here, and thus a content-length is incorrect:
"The 204 response MUST NOT include a message-body, and thus is always terminated by the first empty line after the header fields."
https://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html#sec10.2.5

Clients that assume no body, and thus don't continue reading from the socket can run into issues when, on the next read of continued connection, those N number of bytes are sitting there.

The affected calls appear to be:
DELETE /v2/zones/tasks/imports/<id>
DELETE /v2/zones/tasks/exports/<id>
POST /v2/zones/<id>/tasks/abandon