PdosWorkChain except when tot_magnetization is used

[AndresOrtegaGuerrero]

The PdosWorkChain except when dealing with a calculation were tot_magnetization is considered.
The issue is from this line self.ctx.nscf_fermi = workchain.outputs.output_parameters.dict.fermi_energy

When using tot_magnetization there are two energies fermi_energy_up and fermi_energy_down instead of fermi_energy.

This affects the rest of the logic of the workchain that only considers fermi_energy