http-plugin returns http/501 when connecting via IPv6

[pocki80]

http plugin returns httop/501 when connecting via IPv6. Does not matter if /www/ or /telnet/

home:~$ curl -Iv6 localhost:8000/telnet/olsrv2info%20originator
* About to connect() to localhost port 8000 (#0)
*   Trying ::1...
* connected
* Connected to localhost (::1) port 8000 (#0)
> HEAD /telnet/olsrv2info%20originator HTTP/1.1
> User-Agent: curl/7.26.0
> Host: localhost:8000
> Accept: */*
>
* additional stuff not fine transfer.c:1037: 0 0
* HTTP 1.0, assume close after body
< HTTP/1.0 501 Not Implemented
HTTP/1.0 501 Not Implemented
< Date: Fri, 09 Nov 2018 10:30:46 GMT
Date: Fri, 09 Nov 2018 10:30:46 GMT
< Server: 0.15.1
Server: 0.15.1
< Connection: closed
Connection: closed
< Access-Control-Allow-Origin: *
Access-Control-Allow-Origin: *
< Content-Type: text/html
Content-Type: text/html
< Content-length: 119
Content-length: 119
< Cache-Control: no-cache
Cache-Control: no-cache

<
* Excess found in a non pipelined read: excess = 119 url = /telnet/olsrv2info%20originator (zero-length body)
* Closing connection #0