Small fixes / cleanup for jet and MET validation
Three small issues are addressed in this MR
- fix an issue observed for large-R UFO jets when running NTUP_PHYSVAL in master by checking first if variables that are being retrieved are present
- removal of some histograms that are never filled (because the substructure variables are not reconstructed in master anymore)
- move MET validation histograms out of wrong if statement
Tagging @gcallea @bhodkins @camacho @mleblanc @mswiatlo @schaarsc