IGNITE-5136 is ready for review (GridLogThrottle memory leak)

[Dmitrii Ryabov]

Hello, igniters!
I've done with this ticket, tests are ok. Can you review?

JIRA: https://issues.apache.org/jira/browse/IGNITE-5136
PR: https://github.com/apache/ignite/pull/3236
Upsource (old changes):
https://reviews.ignite.apache.org/ignite/review/IGNT-CR-344
Upsource (new changes):
https://reviews.ignite.apache.org/ignite/review/IGNT-CR-436
CI tests: https://ci.ignite.apache.org/viewLog.html?buildId=1004471&tab=buildResultsDiv&buildTypeId=Ignite20Tests_RunAll