Ensure correct handling of javax.management.Attribute

[nwillems]

This is an issue when connecting to OpenDJ from forgerock.

Steps to reproduce:

• Start OpenDJ and enable JMX
• Configure as below
• List matched attributes and see it showing up
• Collect attributes and see that it is missing(When finally working I had to wait for a second round of collection) - observe "error" in log.

jmx_url: service:jmx:rmi:///jndi/rmi://localhost:1689/org.opends.server.protocols.jmx.client-unknown
user: cn=Directory Manager
password: INSERT YOUR PASSWORD
conf:
    - include:
        domain: org.opends.server
        bean: org.opends.server:Name=rootDSE,Rdn1=cn-monitor,Rdn2=cn-LDAPS_Connection_Handler_0000_port_1636
        attribute:
          ds-connectionhandler-num-connections:
            metric_type: counter
            alias: opendj.num_connections

When investigating I discovered the misconfigured logger in JMXAttribute, that why this is also included.

[yannmh]

Thanks a lot for fixing the issue @nwillems, and sorry for the late answer @nwillems.

I added your contribution to our upcoming milestone. We'll review it shortly :)

[olivielpeau]

Looks good, merging!

Thanks again @nwillems!