double the reserve for on-demand strip cluster from raw (backport of #14953 )

[slava77]

This is a cheap temporary solution (about 2.7 MB cost per stream).
It resolves several crashes reported in HLT step of 810pre7 relvals
https://hypernews.cern.ch/HyperNews/CMS/get/relval/5231.html

[slava77]

@cmsbuild please test

[cmsbuild]

The tests are being triggered in jenkins.
https://cmssdt.cern.ch/jenkins/job/ib-any-integration/13634/console

[cmsbuild]

A new Pull Request was created by @slava77 (Slava Krutelyov) for CMSSW_8_0_X.

It involves the following packages:

RecoLocalTracker/SiStripClusterizer

@cmsbuild, @cvuosalo, @slava77, @davidlange6 can you please review it and eventually sign? Thanks.
@makortel, @forthommel, @yduhm, @GiacomoSguazzoni, @gbenelli, @rovere, @VinInn, @nickmccoll, @jlagram, @gpetruc, @OlivierBondu, @threus this is something you requested to watch as well.
@slava77, @Degano, @smuzaffar you are the release manager for this.

cms-bot commands are list here #13028

[cmsbuild]

+1
Tested at: d7ce6a5
https://cmssdt.cern.ch/SDT/jenkins-artifacts/pull-request-integration/PR-14956/13634/summary.html

[cmsbuild]

Comparison is ready
https://cmssdt.cern.ch/SDT/jenkins-artifacts/pull-request-integration/PR-14956/13634/summary.html

[slava77]

+1

for #14956 d7ce6a5

• jenkins test pass and comparisons show no changes.
• the issue was tested in 81X in double the reserve for on-demand strip cluster from raw  #14953, it is generic across releases.

[cmsbuild]

This pull request is fully signed and it will be integrated in one of the next CMSSW_8_0_X IBs (tests are also fine). This pull request requires discussion in the ORP meeting before it's merged. @slava77, @davidlange6, @Degano, @smuzaffar

[davidlange6]

+1

[slava77]

Just to note: this reserve is not enough for PU100.
PU70 looked OK on a smallish number of events.