Return nil instead of falling back to default port

Author: josevalim

lib/tidewave.rb

@@ -167,7 +167,7 @@ def origin_allowed_path?(path)
   end
 
   def local_port(request)
-    request.get_header("SERVER_PORT").to_i.nonzero? || request.port
+    request.get_header("SERVER_PORT").to_i.nonzero?
   end
 
   def valid_client_ip?(request)