Redmine

Today I realized that the favicon of redmine.org is not displayed, neither in my browser (Firefox 31) nor in my atom feed reader (Thunderbird 31). It seems for me that the icon could be retrieved but has size zero:

 curl -v http://www.redmine.org/favicon.ico?1322400152
* About to connect() to www.redmine.org port 80 (#0)
*   Trying 46.4.36.71...
* connected
* Connected to www.redmine.org (46.4.36.71) port 80 (#0)
> GET /favicon.ico?1322400152 HTTP/1.1
> User-Agent: curl/7.26.0
> Host: www.redmine.org
> Accept: */*
> 
* additional stuff not fine transfer.c:1037: 0 0
* HTTP 1.1 or later with persistent connection, pipelining supported
< HTTP/1.1 200 OK
< Date: Fri, 25 Jul 2014 15:02:00 GMT
< Server: Apache
< Last-Modified: Sun, 27 Nov 2011 13:22:32 GMT
< ETag: "1159493-0-4b2b7474f9600" 
< Accept-Ranges: bytes
< Content-Length: 0
< Content-Type: image/x-icon
< 
* Connection #0 to host www.redmine.org left intact
* Closing connection #0