PowhegControl: fixing Wt_DR_modified, and LHE file filters: removing commented code
requested to merge atlas-physics/pmg/mcexperts/powheg-experts/athena:21.6-RemoveCommentsLHEFilters into 21.6
This fixes the name of the new process Wt_DR_modified (instead of Wt_DR_Modified) in the latest Powheg ATLASOTF-05-03 distribution.
It also removes commented code in lhe filters, introduced in !51572 (merged).
@ewelina I will handle the sweep to master manually.