Some query bonds are replaced with Single bond after saving in SMILES-format

**Steps to reproduce:**

1. Launch Editor.
2. Create any structure, for example, chain.
3. Replace any of the structure bond with single/double bond.
4. Click "Save as..." button.
5. Select Dailigt SMILE format. Click "Save to file".
6. Click "Save as..." button.
7. Select Extended SMILE format. Click "Save to file".
8. Clear the canvas.
9. Open saved at 5 and 7 steps structures one by one.

**Expected result:**

The single/double bond stays at the structure.

**Actual result:**

Single/Double bond is replace with Single bond.
In the table you can see which query bonds are replaced with single bond:

The type of bond | Daylight SMILE | Extended SMILE
-- | -- | --
any bond | Is opened correctly | is replaced with single bond
aromatic bond | Is opened correctly | Is opened correctly
single/Double bond | Is replaced with single bond | Is replaced with single bond. In SMILE-string there are "//"-signs
single/aromatic bond | is replaced with single bond | Is replaced with single bond
Double/aromatic bond | Is replaced with single bond | Is replaced with single bond. In SMILE-string there are "//"-signs