fix: move tracking middleware before host authorization

closes #2415

config/application.rb

@@ -34,7 +34,7 @@ module Postal
 
     # Load the tracking server middleware
     require "postal/tracking_middleware"
-    config.middleware.use Postal::TrackingMiddleware
+    config.middleware.insert_before ActionDispatch::HostAuthorization, Postal::TrackingMiddleware
 
     config.logger = Postal.logger_for(:rails)