[Doc] ActiveMQ Web Console credentials should be configured in etc/org.apache.activemq.webconsole.cfg

In the JBoss A-MQ release the ActiveMQ Web Console credentials should be configured in etc/org.apache.activemq.webconsole.cfg

The following documentation:

https://access.redhat.com/site/documentation/en-US/JBoss_A-MQ/6.0/html/Managing_and_Monitoring_a_Broker/files/FMQAdminBasicSecConfig.html

Should be updated to reflect this change. This is alread y documented in the JBoss Fuse 6.0 doc:

https://access.redhat.com/site/documentation/en-US/JBoss_Fuse/6.0/html/Configuring_and_Running_JBoss_Fuse/files/BasicSec.html