Fix error

config/initializers/trusted_proxies.rb

@@ -1,7 +1,11 @@
 module Rack
   class Request
     def trusted_proxy?(ip)
+      if Rails.application.config.action_dispatch.trusted_proxies.nil?
+        super
+      else
         Rails.application.config.action_dispatch.trusted_proxies.any? { |proxy| proxy === ip }
       end
     end
   end
+end