Fix exception on MasshunterQuant file import

https://github.com/bikalabs/Bika-LIMS/commit/4d61643eb7a08c2430cdb7a2077f08a43ad819f2

To take into account for further merge of instrument-interfaces branch to master.
After instrument-interfaces branch, the interfaces folder structure changed and the
MasshunterQuantCSVFileParser (from agilent/masshunter_quant.py) has been replaced by
agilent/masshunter/quantitative.py