RFR: JDK-8056057 - NPE to throw by PulseCounterConfig when controllerName is null

[alexey mironov]

issue: https://bugs.openjdk.java.net/browse/JDK-8056057
webrev: http://cr.openjdk.java.net/~alkonsta/8056057

Hi All,

Please review the changes made in order to fix issue with NPE in 
PulseCounterConfig class.

Regards,
Alexey