installer: de-duplex activemq network connectors (bug 1066729)

https://bugzilla.redhat.com/show_bug.cgi?id=1066729
Procedure 7.20. To Configure a Network of ActiveMQ Brokers
Links to a broker configuration which uses duplex
NetworkConnectors. These duplex network connectors need only be
configured from the initiating broker, not on both sides of the
connection.