When I search the internet, I see the same database problem occur for some Python users. In the posting I looked at, the user showed that the request was being rejected by the other end, as opposed to a status of "not found". Some users there found that they were able to access later, but not consistently.
At the moment I do not know if there is a firewall configured to deny access (to most of us), or if there is a firewall that is rejecting "high load", or if the people who run the site have decided to remove the files. At the very least you will need to try again later, and it is not currently clear whether the file will ever be available again.
I did not find any alternative source for the file.
