DRILL-6702: Disable CPU Reporting for non-HotSpot JDKs
When running Drill on the IBM JDK (J9), the webUI throws an ClassCastException :
Caused by: java.lang.ClassCastException: com.ibm.lang.management.ExtendedOperatingSystem incompatible with com.sun.management.OperatingSystemMXBean
This PR simply disables that, since Drill should ideally be recompiled with these alternative JDKs.
