Fix the access to PU info in HLT Ntuples (91X, master branch)

[ndaci]

Context: HLT Ntuples produced and used by STEAM to perform Rate studies.

Goal: Make the access to PU info independent from the presence of simTracks/simVertices in the input files.

91X version of #17930

[cmsbuild]

A new Pull Request was created by @ndaci for master.

It involves the following packages:

HLTrigger/HLTanalyzers

@Martin-Grunewald, @silviodonato, @cmsbuild, @fwyzard, @davidlange6 can you please review it and eventually sign? Thanks.
@Martin-Grunewald this is something you requested to watch as well.
@Muzaffar, @davidlange6, @smuzaffar you are the release manager for this.

cms-bot commands are listed here #13028

[Martin-Grunewald]

please test

[cmsbuild]

The tests are being triggered in jenkins.
https://cmssdt.cern.ch/jenkins/job/ib-any-integration/18421/console Started: 2017/03/14 21:09

[cmsbuild]

+1
Tested at: 87f633b
https://cmssdt.cern.ch/SDT/jenkins-artifacts/pull-request-integration/PR-17932/18421/summary.html

[cmsbuild]

Comparison job queued.

[cmsbuild]

Comparison is ready
https://cmssdt.cern.ch/SDT/jenkins-artifacts/pull-request-integration/PR-17932/18421/summary.html

[Martin-Grunewald]

+1

[cmsbuild]

This pull request is fully signed and it will be integrated in one of the next master IBs (tests are also fine). This pull request requires discussion in the ORP meeting before it's merged. @Muzaffar, @davidlange6, @smuzaffar

[davidlange6]

+1