some atoms in the product was not mapped for the reaction

some atoms in the product was not mapped.

```py
from indigo import *
indigo = Indigo()
def addmapbyINDIGO(rxnsmi):
smi = rxnsmi
rxn = indigo.loadReaction(smi)
rxn.automap('discard ignore_charges ignore_isotopes ignore_valence ignore_radicals')
# rxn.automap('discard')

rxnsmi_map_indigo = rxn.smiles()
return rxnsmi_map_indigo
rxnsmi = "CC(C)(C)OC(=O)Nc1ncc(C=O)s1.C[Si](C)(C)C#N>>CC(C)(C)OC(=O)Nc1ncc(C(O)CN)s1"

addmapbyINDIGO(rxnsmi)
```

output is
```
'[CH3:1][C:2]([O:5][C:6]([NH:8][c:9]1[s:15][c:12]([CH:13]=[O:14])[cH:11][n:10]1)=[O:7])([CH3:4])[CH3:3].C[Si](C#N)(C)C>>[CH3:1][C:2]([O:5][C:6]([NH:8][c:9]1[s:15][c:12]([CH:13](CN)[OH:14])[cH:11][n:10]1)=[O:7])([CH3:4])[CH3:3]'
```

The CN atoms in the product were not mapped.