fix duplicate customise_commands in cmsDriver

[kpedro88]

For a while, I've noticed that using customise_commands in cmsDriver resulted in the commands being printed twice at the end of the generated config. The handling of this was changed most recently in #6492.

I finally found the cause of the duplication: the second call to addCustomise() for unscheduled mode was in the wrong block for the current logic. The fixed version works for both the example in #6492 and regular (scheduled) examples, e.g.:

cmsDriver.py SinglePiE50HCAL_pythia8_cfi --python_filename run_step1_noCT.py --conditions auto:phase1_2017_design -n 10 --era Run2_2017 --geometry Configuration.Geometry.GeometryExtended2017dev_cff,Configuration.Geometry.GeometryExtended2017devReco_cff --eventcontent FEVTDEBUGHLT -s GEN,SIM,DIGI:pdigi_valid --datatier GEN-SIM-DIGI-RAW-HLTDEBUG --beamspot Realistic50ns13TeVCollision --fileout file:step1_noCT.root --customise SLHCUpgradeSimulations/Configuration/HCalCustoms.customise_Hcal2017Full --customise_commands "process.mix.digitizers.hcal.he.sipmCrossTalk = cms.double(0)" --no_exec

[kpedro88]

@cmsbuild please test

[cmsbuild]

The tests are being triggered in jenkins.
https://cmssdt.cern.ch/jenkins/job/ib-any-integration/14463/console

[cmsbuild]

A new Pull Request was created by @kpedro88 (Kevin Pedro) for CMSSW_8_1_X.

It involves the following packages:

Configuration/Applications

@cmsbuild, @franzoni, @davidlange6 can you please review it and eventually sign? Thanks.
@ghellwig, @Martin-Grunewald this is something you requested to watch as well.
@slava77, @smuzaffar you are the release manager for this.

cms-bot commands are list here #13028

[cmsbuild]

+1
Tested at: efa4fa8
https://cmssdt.cern.ch/SDT/jenkins-artifacts/pull-request-integration/PR-15418/14463/summary.html

[cmsbuild]

Comparison is ready
https://cmssdt.cern.ch/SDT/jenkins-artifacts/pull-request-integration/PR-15418/14463/summary.html

[davidlange6]

@kpedro88 - hum, I don't think this is the real bug as the set of customize commands should be orthogonal for the two function calls - but thanks for providing an example of the problem. Thinking.