Protect FlexiLoader against no HE

[bsunanda]

Protect HcalFlexiGeometryLoader

[cmsbuild]

A new Pull Request was created by @bsunanda for CMSSW_6_2_X_SLHC.

Protect FlexiLoader against no HE

It involves the following packages:

Geometry/HcalCommonData
Geometry/HcalTowerAlgo

@civanch, @Dr15Jones, @ianna, @mdhildreth, @cmsbuild, @nclopezo, @Degano, @ktf can you please review it and eventually sign? Thanks.
@ghellwig this is something you requested to watch as well.
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@andersonjacob, @mark-grimes you are the release manager for this.
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[ianna]

+1

[cmsbuild]

This pull request is fully signed and it will be integrated in one of the next CMSSW_6_2_X_SLHC IBs unless changes or unless it breaks tests. @andersonjacob, @mark-grimes can you please take care of it?

[mark-grimes]

merge

Tested with #2627. See the notes there.