Fix the input file writer

This at least prevents it from crashing. Works in
conjunction with https://github.com/pierrelb/RMG-Py/commit/fc4deeb082308788abe43e72e6dd0a97ee4a1eae in RMG-Py.

The original quantities were changed from getValueInGivenUnits()
to just getValue(). That needed to be updated across the
website input file writing scripts.