added extension bouton to en_construction dossiers bound to expire

config/routes.rb

@@ -146,6 +146,7 @@ Rails.application.routes.draw do
       post '/carte/zones' => 'carte#zones'
       get '/carte' => 'carte#show'
       post '/carte' => 'carte#save'
+      post '/repousser-expiration' => 'dossiers#extend_conservation'
     end
 
     # Redirection of legacy "/users/dossiers" route to "/dossiers"