Change gem user agent

How do I change the gem user agent? We are behind a proxy server which
does not allow the gem user agent.

I checked /usr/lib/ruby/1.8/rubygems/ on Ubuntu.


It’s in
lines 316-319 on my rubygems 1.3.7. Normally I wouldn’t suggest
it in the files directly but I don’t see a convenient way to get around

-Jonathan N.