Add note to configuring messaging guide that JDBC journal with repliated HA is not supported

Document into Confiugring Messaging guide for EAP 7.4. and EAP 8 that  that JDBC journal with repliated HA is not supported. It's expected that replication would be done on DB level as it's more effective than replicating JDBC journal records through Artemis. 

 This might be a note in chapter https://access.redhat.com/documentation/en-us/red_hat_jboss_enterprise_application_platform/7.4/html-single/configuring_messaging/index#messaging_ha_jdbc_persistence