schedule PrCheckerEfficiencyPlots_HLT2 test and move to gcc8
to be merged after lhcb-datapkg/PRConfig!72 (merged) and LHCbPR2HD!134 (merged)
Edited by Maciej Pawel Szymanski
to be merged after lhcb-datapkg/PRConfig!72 (merged) and LHCbPR2HD!134 (merged)