Update config/routes.rb

Co-authored-by: Greg Annandale <greg@raspberrypi.org>

Author: patch0

config/routes.rb

@@ -4,7 +4,7 @@
   # Dummy routes. These routes are never reached in the app, as Omniauth
   # intercepts it via Rack middleware before it reaches Rails, however adding
   # them allows us to use rpi_auth_login_path helpers etc.
-  post '/auth/rpi', as: :rpi_auth_login
+  post '/auth/rpi', as: :rpi_auth_login, params: { login_options: 'v1_signup' }
   post '/auth/rpi', as: :rpi_auth_signup, params: { login_options: 'force_signup,v1_signup' }
 
   namespace 'rpi_auth' do