Fix xAOD::TruthVertex matching logic in InDetSecVtxTruthMatchTool
Fix logic in InDetSecVtxTruthMatchTool::matchVertices and InDetSecVtxTruthMatchTool::checkProduction.
Valid truth vertex barcode/id values are negative integers. This code was using the value -1 to indicate "no match", but this value is a possibly correct vertex barcode, so some actual matches could have been ignored. The code has been updated to use HepMC::INVALID_VERTEX_ID
(=1) instead.