Configuring for RabbitMQ using the grouper.messaging .password works but .password.elConfig does not.  See below.  While I am reporting this on 2.6.13 I think this has been an issue for some time - just getting around to reporting it.

grouper.messaging.system.rabbitmqSystem.password.elConfig = ${java.lang.System.getenv().get('RABBITMQ_PASSWORD_FILE') != null ? org.apache.commons.io.FileUtils.readFileToString(new("java.io.File", java.lang.System.getenv().get('RABBITMQ_PASSWORD_FILE')), "utf-8") : java.lang.System.getenv().get('RABBITMQ_PASSWORD') }