Fix bug in PDBLoader for Histidine protonation
Fix bug in PDBLoader for Histidine protonation

PDBLoader module was checking the wrong atom name for establishing histidine
protonation

AdaptivePELE/AdaptivePELE,AdaptivePELE/AdaptivePELE,AdaptivePELE/AdaptivePELE,AdaptivePELE/AdaptivePELE