InChI molecule with amide groups is rendered incorrectly

[Original bug report from GGA repository](https://github.com/ggasoftware/indigo/issues/16)
When L-glutamine is loaded from InChI, double bond is between the `C=N` instead of `C=O`.
```python
from indigo import Indigo
from indigo_inchi import IndigoInchi
from indigo_renderer import IndigoRenderer

i = Indigo()
ii = IndigoInchi(i)
ir = IndigoRenderer(i)
inchi_m = ii.loadMolecule('InChI=1S/C5H10N2O3/c6-3(5(9)10)1-2-4(7)8/h3H,1-2,6H2,(H2,7,8)(H,9,10)/t3-/m0/s1')
ir.renderToFile(m, 'inchi.png')
smiles_m = i.loadMolecule(inchi_m.smiles())
ir.renderToFile(m, 'smiles.png')
```
smiles.png:
inchi.png: