Fix the bug when calling QGTagger for updated jets

[youyingli]

Fix the bug when choosing updateCollection with QGTagger. The error will be

----- Begin Fatal Exception 10-Mar-2020 15:04:25 CET-----------------------
An exception of category 'InvalidReference' occurred while
   [0] Processing  Event run: 1 lumi: 2353 event: 2352007 stream: 0
   [1] Running path 'Path'
   [2] Prefetching for module ...
   [3] Prefetching for module PATJetSelector/'selectedPatJetsAK4PFCHS'
   [4] Calling method for module PATJetUpdater/'updatedPatJetsTransientCorrectedAK4PFCHS'
Exception Message:
ValueMap: no associated value for given product and index
----- End Fatal Exception -------------------------------------------------

[alefisico]

thanks @youyingli for this PR. I'll try to validate it asap and merge it if needed.