You can clone with
HTTPS or Subversion.
(Imported from Trac #679, reported by jbapple on 2010-05-04)
(Imported comment by ross on 2010-05-04)
The package pages also contain a link to the .cabal file, so munging the address on the page alone might not make much difference. There's the tarball too, but presumably not all crawlers will take that apart.
This doesn't seem like it should be on this repo at all, since it's related to a Hackage web-site issue. Anyway there is no activity since 2010, so I propose closing. Please re-open or create another issue if there is a problem with email addresses in Cabal files.