changes to connector host and port not persisted in geronimo

Hostname and port changes I made to the activemq connectors via the geronimo admin console don't get persisted in geronimo's var/config/config.xml, causing them to revert to their original values when the server restarts.

To fix this problem ActiveMQConnectorGBean needs to declare the host and port attributes as manageable when it creates its gbeaninfo. See the attached patch.