Removing unnecessary file
File cluster.geo.root should be read from /cvmfs, not from the Athena share folder. The removed file is the same as /cvmfs/atlas.cern.ch/repo/sw/database/GroupData/HIJetCorrection/cluster.geo.DATA_2015.root. Several other files with weights are also present in the same folder.
Changed the setup, so it reflects this and is consistent with HITowerWeightTool setup.
(N.B.: this won't solve ATLHI-469 nor ATLHI-472, although the problem is in reading zero weights from this (or similar) file.)