RFR (trivial): 8236552: Description of jmxremote.ssl.config.file in ManagementAgent.start is incorrect

[Yasumasa Suenaga]

Hi all,

Please review this trivial fix:

   JBS: https://bugs.openjdk.java.net/browse/JDK-8236552
   webrev: http://cr.openjdk.java.net/~ysuenaga/JDK-8236552/webrev.00/

ManagementAgent.start dcmd provides jmxremote.ssl.config.file for SSL configuration. We can see description as below:

```
jmxremote.ssl.config.file : [optional] set com.sun.management.jmxremote.ssl_config_file (STRING, no default value)
```

This option would set com.sun.management.jmxremote.ssl.config.file, not ssl_config_file.


Thanks,

Yasumasa