Comment # 1 on bug 1050557 from Ladislav Slez�k

Currently the http://download.opensuse.org/update/tumbleweed/ 
 URL is redirected to
http://download.opensuse.org/repositories/openSUSE:/Factory:/Update/standard
and the repository refresh work for me correctly.

I guess it was a temporary issue on the server, probably the repository was
being updated. Try it again.

Resolving as WORKSFORME.