Fix arguments in `mc_unpackers`
Fixes bug introduced by a late to change to LHCb!3395 (merged) that was not mirrored in !1299 (merged).
See LHCb#189 for more info on discussion around use of output_level
and bind
Edited by Nicole Skidmore
Fixes bug introduced by a late to change to LHCb!3395 (merged) that was not mirrored in !1299 (merged).
See LHCb#189 for more info on discussion around use of output_level
and bind