.well-known login bug (new login)

- go to https://riot.im/#/login
- type in @tom:lant.uk
- type in your very excellent password
- realise that matrix.org isn't your homeserver
- click 'Advanced/Other'
- see that your HS details have been populated by .well-known
- click login
- see that the login request still goes to matrix.org

if you delete/retype the final k in https://matrix.lant.uk then it works properly