Some query bonds are replaced with Single bond after converting Mol into SMILES-format

**Steps to reproduce:**

1. Create Mol file that contains the following types of bonds: 5, 6, 7, 8 (or use
[mol_example.zip](https://github.com/epam/Indigo/files/5616477/mol_example.zip))
2. Convert created Mol file into Extended SMILES by calling /v2/indigo/convert.
4. Convert generated SMILES file into Mol format by calling /v2/indigo/layout
5. Compare original and generated Mol files.

**Expected result:**

Bond types from original model are equal to bond types from generated model.

**Actual result:**

Bond types 5, 6, 7, 8 in resulted model are replaced by 1.