Add back 2016 beamgas lines
The following lines were not active following changes for the 2016 pPb run:
- Hlt1BeamGasBeam1VeloOpen
- Hlt1BeamGasBeam2VeloOpen
- Hlt1BeamGasHighRhoVertices
I brought back the list of active lines to the 2016 pp state. In addition, I improved the Hlt1Line.clone logic and got rid of two configuration warnings.