Change mayConsume to conditional consumes in PATJetProducer

[Dr15Jones]

Changed from a mayConsume to a conditionally called consumes since
the call to getByToken is governed by another parameter known at
configuration time. Only if the other parameter is true will we
call consumes.

[cmsbuild]

A new Pull Request was created by @Dr15Jones (Chris Jones) for CMSSW_7_6_X.

Change mayConsume to conditional consumes in PATJetProducer

It involves the following packages:

PhysicsTools/PatAlgos

@cmsbuild, @vadler, @monttj can you please review it and eventually sign? Thanks.
@rappoccio, @imarches, @ahinzmann, @acaudron, @mmarionncern, @jdolen, @nhanvtran, @schoef, @ferencek, @gpetruc, @mariadalfonso, @pvmulder, @TaiSakuma this is something you requested to watch as well.
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[Dr15Jones]

please test

[cmsbuild]

The tests are being triggered in jenkins.

[cmsbuild]

+1
Tested at: 824d929
https://cmssdt.cern.ch/SDT/jenkins-artifacts/pull-request-integration/PR-11401/8242/summary.html

The following merge commits were also included on top of IB + this PR after doing git cms-merge-topic:
c9e8b10
889df4f
You can see more details here:
https://cmssdt.cern.ch/SDT/jenkins-artifacts/pull-request-integration/PR-11401/8242/git-log-recent-commits
https://cmssdt.cern.ch/SDT/jenkins-artifacts/pull-request-integration/PR-11401/8242/git-merge-result

[cmsbuild]

Comparison is ready
https://cmssdt.cern.ch/SDT/jenkins-artifacts/pull-request-integration/PR-11401/8242/summary.html