update HION5.py for gamma+jet analysis

As requested by gamma+jet analysis team, the following changes are implemented:

• Additional variables: etcone20, etcone30, etcone40, Loose
• The minimum photon pT cut of 30 GeV would be good (instead of 40 GeV)
• photon trigger HLT_g20_loose_ion (already in previous HION5)

tag @kburka and @ygo