[rabbitmq-discuss] Bug in Management plugin port redirect in 3.0.0

[Chris Griego]

The redirect response from the management plugin (I believe ultimately
the fault lies with rabbitmq-mochiweb) is malformed and can cause some
HTTP clients to hang, including curl.

```
$ curl -i http://localhost:55672/
HTTP/1.1 301 Moved Permanently
Server: MochiWeb/1.0 (Any of you quaids got a smint?)
Location: http://localhost:15672/

Date: Fri, 23 Nov 2012 05:18:56 GMT
Content-Length: 0

```

The Location header has a newline in it, causing the HTTP client to
treat the rest of the response as the body, meaning they don't
interpret the Content-Length: 0 header. In some HTTP clients that
causes the hang because the client is still expecting there to be more
to the body.