Remove boolean flag from post login route
Remove boolean flag from post login route

Version 2.0 of the apiclient removed the need for a boolean flag as to
whether the user is a supplier or not. It's removed from the login
routes here to comply with the change.

alphagov/digitalmarketplace-admin-frontend,alphagov/digitalmarketplace-admin-frontend,alphagov/digitalmarketplace-admin-frontend,alphagov/digitalmarketplace-admin-frontend