Hoy can I change the log4j level in WildFly server?

I'm logging in a Groovy script using:

Logger logger = Logger.getLogger("org.bonitasoft");
logger.info("Test log");

It works fine in development environment, but in the production server I canĀ“t see the logs in server.log file.

I tried modifying standalone.xml and logging.properties, but when I restart the server it changes again to 'WARN'.

Is it possible to do this or I should debug using the WARN level?

Thank you very much.