Failed to write "discovery-group-name" attribute of ConnectionFactory in EAP 6.1

Issue

I want to configure discovery-group-name to JMS connection-factories but the following CLI commend fails in EAP 6.1. It worked in EAP 6.0.x:

[standalone@localhost:9999 /] /subsystem=messaging/hornetq-server=default/connection-factory=RemoteConnectionFactory:write-attribute(name=discovery-group-name,value=dg-group1)
{
    "outcome" => "failed",
    "failure-description" => "JBAS011630: Alternative attribute of (discovery-group-name) is already defined.",
    "rolled-back" => true
}

Also it looks I cannot undefine predefined connector for connection-factory:

[standalone@localhost:10099 /] /subsystem=messaging/hornetq-server=default/connection-factory=RemoteConnectionFactory:undefine-attribute(name=connector)
{
    "outcome" => "failed",
    "failure-description" => "JBAS014749: Operation handler failed: JBAS011664: Runtime handling for connector is not implemented",
    "rolled-back" => true
}