Fix deprecation warning calling `env' in controllers

app/controllers/users/omniauth_callbacks_controller.rb

@@ -25,7 +25,7 @@ class Users::OmniauthCallbacksController < Devise::OmniauthCallbacksController
     def sign_in_with(feature, provider)
       raise ActionController::RoutingError.new("Not Found") unless Setting["feature.#{feature}"]
 
-      auth = env["omniauth.auth"]
+      auth = request.env["omniauth.auth"]
 
       identity = Identity.first_or_create_from_oauth(auth)
       @user = current_user || identity.user || User.first_or_initialize_for_oauth(auth)