Thread:Project:Support desk/Upload slow/reply

I found the problem: when I upload a file, it tries to connect to

http://commons.wikimedia.org/w/api.php?aisha1base36=j4xs0i3rn6unupzfn8bwcs2kyo54cfy&aiprop=timestamp%7Cuser%7Ccomment%7Curl%7Csize%7Csha1%7Cmetadata%7Cmime&list=allimages&format=json&action=query&redirects=true

But the server stays behind a proxy und is only accessible from the local network. Can I turn this connections off or can I set the http proxy for mediawiki?