JolokiaCollector collects all mbeans regardless of mbeans argument configuration

[alekiv]

From documentation:
mbeans argument - Pipe delimited list of MBeans for which to collect stats. If not provided, all stats will be collected.

Actually collector collects all mbeans regardless of configured mbeans. "mbeans" list or regex is used just for filtering out actual mbeans from big list of domain obj. It becomes problem with CassandraJolokiaCollector, since there are much data in JMX and diamond just can't get all data in reasonable time.

Proposal: change Jolokia collector logic and read specified mbeans only if "mbeans" list is set, instead of reading domains all data

[shortdudey123]

Feel free to submit a PR.