The qa-config.php file is loaded in each request you perform. So if you change the file you should see the effect starting in the following request.
Welcome to the Q&A site for Question2Answer.
If you have a question about Q2A, please ask in English.
To report a bug, please create a new issue on Github or ask a question here with the bug tag.
If you just want to try Q2A, please use the demo site.