Calculator section in the settings file should not be needed

[chemphys]

The calculator section of the settings file is still necessary, although the argument of any function that needs the software used to perform electronic structure calculations always passes the software itself, along with the database.

Example of this behavior in https://github.com/paesanilab/MB-Fit/blob/master/mbfit/configurations/geometry_optimizer.py#L25

A part from the log path and the molecule section, nothing else should be needed there.