update the B-Field configuration at beginRun in SimG4Core/GeometryProducer

[mmusich]

PR description:

This simple fix allows to be able to run the G4 refitting for alignment purposes on real data preventing a segfault, when crossing run boundaries described to occur in this thread.

PR validation:

The test configuration at /afs/cern.ch/cms/CAF/CMSALCA/ALCA_TRACKERALIGN/MP/MPproduction/mp3344/jobData/job181/ the.py runs successfully (caveat for testing, the changes at: cms-trackeralign:g4Refitting_10_6_X need to be merged first).

if this PR is a backport please specify the original PR and why you need to backport that PR:

This PR is not a backport, but will be backported to all active releases for alignment purposes.

[cmsbuild]

The code-checks are being triggered in jenkins.

[cmsbuild]

+code-checks

Logs: https://cmssdt.cern.ch/SDT/code-checks/cms-sw-PR-31203/17852

• This PR adds an extra 12KB to repository

[cmsbuild]

A new Pull Request was created by @mmusich (Marco Musich) for master.

It involves the following packages:

SimG4Core/GeometryProducer

@cmsbuild, @civanch, @mdhildreth can you please review it and eventually sign? Thanks.
@makortel, @rovere, @fabiocos, @slomeo this is something you requested to watch as well.
@silviodonato, @dpiparo, @qliphy you are the release manager for this.

cms-bot commands are listed here

[mmusich]

@cmsbuild, please test

[cmsbuild]

The tests are being triggered in jenkins.

• CMSSW_11_2_X_2020-08-20-2300/slc7_amd64_gcc820: https://cmssdt.cern.ch/jenkins/job/ib-run-pr-tests/8852/console Started: 2020/08/21 16:41

[cmsbuild]

+1
Tested at: 596d670
https://cmssdt.cern.ch/SDT/jenkins-artifacts/pull-request-integration/PR-43a6f7/8852/summary.html
CMSSW: CMSSW_11_2_X_2020-08-20-2300
SCRAM_ARCH: slc7_amd64_gcc820

[cmsbuild]

Comparison job queued.

[cmsbuild]

Comparison is ready
https://cmssdt.cern.ch/SDT/jenkins-artifacts/pull-request-integration/PR-43a6f7/8852/summary.html

Comparison Summary:

• No significant changes to the logs found
• Reco comparison results: 4 differences found in the comparisons
• DQMHistoTests: Total files compared: 35
• DQMHistoTests: Total histograms compared: 2608222
• DQMHistoTests: Total failures: 7
• DQMHistoTests: Total nulls: 0
• DQMHistoTests: Total successes: 2608193
• DQMHistoTests: Total skipped: 22
• DQMHistoTests: Total Missing objects: 0
• DQMHistoSizes: Histogram memory added: 0.0 KiB( 34 files compared)
• Checked 149 log files, 22 edm output root files, 35 DQM output files

[civanch]

+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 will now be reviewed by the release team before it's merged. @silviodonato, @dpiparo, @qliphy (and backports should be raised in the release meeting by the corresponding L2)

[qliphy]

+1