MCTruthClassifier: Added PDG ID of vector leptoquark (U1)

Fixed classification of electron, muon and tau etc. so that those from decay of vector leptoquark (https://gitlab.cern.ch/atlas-generators-team/MadGraphModels/-/tree/master/vector_LQ_UFO) can be properly identified. Without this patch they are classified as "Unknown" in TRUTH3 derivation. This has been tested by running Reco_tf.py with EVNT file generated with the UFO model above.