fix some leaks in the SWIG wrappers (#4916)
fix some leaks in the SWIG wrappers (#4916)


ptosco/rdkit,ptosco/rdkit,bp-kelley/rdkit,rdkit/rdkit,ptosco/rdkit,rdkit/rdkit,ptosco/rdkit,ptosco/rdkit,bp-kelley/rdkit,ptosco/rdkit,bp-kelley/rdkit,greglandrum/rdkit,rdkit/rdkit,greglandrum/rdkit,rdkit/rdkit,bp-kelley/rdkit,greglandrum/rdkit,bp-kelley/rdkit,rdkit/rdkit,bp-kelley/rdkit,greglandrum/rdkit,bp-kelley/rdkit,ptosco/rdkit,ptosco/rdkit,greglandrum/rdkit,rdkit/rdkit,bp-kelley/rdkit,rdkit/rdkit,rdkit/rdkit,greglandrum/rdkit,greglandrum/rdkit,greglandrum/rdkit