HEAD request to http://redis.io returns 404 Not Found

[samuelcolvin]

With a GET request redis.io returns 200 as expected.

> curl -X GET -vso /dev/null http://redis.io/
*   Trying 109.74.203.151...
* Connected to redis.io (109.74.203.151) port 80 (#0)
> GET / HTTP/1.1
> Host: redis.io
> User-Agent: curl/7.43.0
> Accept: */*
> 
< HTTP/1.1 200 OK
...(rest of response as expected)

However with a HEAD request it returns 404:

> curl -X HEAD -vso /dev/null http://redis.io/
*   Trying 109.74.203.151...
* Connected to redis.io (109.74.203.151) port 80 (#0)
> HEAD / HTTP/1.1
> Host: redis.io
> User-Agent: curl/7.43.0
> Accept: */*
> 
< HTTP/1.1 404 Not Found
< Date: Sat, 17 Sep 2016 20:42:50 GMT
< Status: 404 Not Found
< Content-Type: text/html
< Via: 1.1 redis.io
< Vary: Accept-Encoding
* no chunk, no close, no size. Assume close to signal end
< 

This might seem irrelevant but it's causing sphinx's linkcheck to return WARNING: broken link: http://redis.io/.

[audriusk]

Package version tracking website Repology has encountered the same issue (repology/repology#211) with HEAD request returning 404, which makes redis.io to be reported as a broken URL for packages that point to it as their homepage.