Correction of an instruction in fancy indexing
Correction of an instruction in fancy indexing

Fields of fancy indexing has to be homogeneous, so i'll change the field `single` which is a duplicate with `per_child`.
openfisca/openfisca-doc,openfisca/openfisca-doc,openfisca/openfisca-doc,openfisca/openfisca-doc