Use 504 gateway timeout for rack-timeout errors

Author: Redande

app/controllers/application_controller.rb

@@ -43,11 +43,11 @@ class ApplicationController < ActionController::Base
   end
 
   rescue_from Rack::Timeout::RequestTimeoutException do |exception|
-    respond_with_error('Request timed out', 503, exception) # status code 408 would be the correct status code, but when receiving 408 Firefox retries 10 times and then states the connection was reset instead of showing our error
+    respond_with_error('Request timed out', 504, exception) # status code 408 would be the correct status code, but when receiving 408 Firefox retries 10 times and then states the connection was reset instead of showing our error
   end
 
   rescue_from Rack::Timeout::RequestTimeoutError do |exception|
-    respond_with_error('Request timed out', 503, exception) # status code 408 would be the correct status code, but when receiving 408 Firefox retries 10 times and then states the connection was reset instead of showing our error
+    respond_with_error('Request timed out', 504, exception) # status code 408 would be the correct status code, but when receiving 408 Firefox retries 10 times and then states the connection was reset instead of showing our error
   end
 
   before_action :set_default_url_options