Replacing PR#5954: Threadsafe faster hcal25ns reco method2

 A new PR. This is the SAME as the latest update of the PR#5954 and meant to replace that (with a fresh pull request...)

(ref: PR#5954: https://github.com/cms-sw/cmssw/pull/5954)
why is this removed?
@abdoulline
Salavat, should this line stay?