Assume BCrypt::Errors::InvalidHash exceptions are bad login requests
Assume BCrypt::Errors::InvalidHash exceptions are bad login requests

If a user has a new-style password but their sign in fails the code
will try to check if it's a valid old-style password which causes
an exception. That exception means the password is invalid.

alphagov/signonotron2,alphagov/signonotron2,alphagov/signonotron2,alphagov/signonotron2