fix race condition in MSRPChat.end

darcs-hash:20090320142655-b2873-a0a30099a6523c8f779f4406d2503e80fb9d6217
Set TLS config ca_list_file to None and verify_server to False by default

darcs-hash:20090320150821-58103-60b17101125c147b5c925755e2432a99a79c3639