put in failsafe to not run PreMixing and HIP simulation simultaneously

[boudoul]

This is preventing to run premixing when switching on the HIP simulation

Forward port of the last commit from @mdhildreth in the 80X PR #15458 , keeping all release cycles in synch

[cmsbuild]

A new Pull Request was created by @boudoul (boudoul) for CMSSW_8_1_X.

It involves the following packages:

SimTracker/SiStripDigitizer

@cmsbuild, @civanch, @mdhildreth, @davidlange6 can you please review it and eventually sign? Thanks.
@makortel, @sdevissc, @GiacomoSguazzoni, @jlagram, @rovere, @VinInn, @cnuttens, @prolay, @threus, @dgulhan, @LBeck this is something you requested to watch as well.
@slava77, @smuzaffar you are the release manager for this.

cms-bot commands are listed here #13028

[civanch]

please test

[cmsbuild]

The tests are being triggered in jenkins.
https://cmssdt.cern.ch/jenkins/job/ib-any-integration/16859/console Started: 2016/12/08 11:14

[cmsbuild]

+1
Tested at: e6f5bb2
https://cmssdt.cern.ch/SDT/jenkins-artifacts/pull-request-integration/PR-16905/16859/summary.html

[cmsbuild]

Comparison job queued.

[cmsbuild]

Comparison is ready
https://cmssdt.cern.ch/SDT/jenkins-artifacts/pull-request-integration/PR-16905/16859/summary.html

[civanch]

+1

[cmsbuild]

This pull request is fully signed and it will be integrated in one of the next CMSSW_8_1_X IBs (tests are also fine). This pull request requires discussion in the ORP meeting before it's merged. @slava77, @davidlange6, @smuzaffar

[davidlange6]

+1