TrigGlobEffCorrTool bug fix for rarely-used trigger combination
@tadej found a bug in the function in charge of computing efficiencies for combinations of at least three single-lepton triggers involving exactly two different lepton flavours. This is a combination that is typically not needed, as both egamma and muon CP groups provide scale factors (and efficiencies) directly for the logical OR of the relevant unprescaled single-lepton triggers.
The faulty behaviour would be easily noticeable by hypothetical users: frequent CP::CorrectionCode:Error return values accompanied by error messages. The latter would originate from tentatives to retrieve trigger-leg efficiencies for the wrong type of object.
This merge request fixes the bug.