[C2hs] Appologies about recent spammage, should be blocked now

Sorry about the spam/phishing/thing stuff was getting though. Should be blocked now. The senders were spoofing an @haskell.org address which I'd had it set up to automatically accept. I've changed the mailing list to just accept cvs-ghc@haskell.org since that's the address the trac updates come from. Duncan