Use correct settings key for python location.
Use correct settings key for python location.

The quantumInput prefix was removed when the PythonScript class
was added.

Change-Id: If0b770e9e3975b485e4a183256cd1626d120051b

ghutchis/avogadrolibs,cjh1/mongochemweb-avogadrolibs,wadejong/avogadrolibs,ghutchis/avogadrolibs,ghutchis/avogadrolibs,OpenChemistry/avogadrolibs,ghutchis/avogadrolibs,cjh1/mongochemweb-avogadrolibs,OpenChemistry/avogadrolibs,ghutchis/avogadrolibs,OpenChemistry/avogadrolibs,cjh1/mongochemweb-avogadrolibs,OpenChemistry/avogadrolibs,cjh1/mongochemweb-avogadrolibs,wadejong/avogadrolibs,wadejong/avogadrolibs,wadejong/avogadrolibs,OpenChemistry/avogadrolibs