Look over warnings in 'Structure check' for molecules with R-Groups

Affected versions: Remote, Standalone

'Structure check' of a molecule with R-Group shows less warnings than of the similar molecule without R-Group.

Steps to reproduce:
1. Execute /v2/indigo/check with the following parameters:
struct
[ketcher (3).zip](https://github.com/epam/Indigo/files/6316310/ketcher.3.zip)
options: {smart-layout: true, ignore-stereochemistry-errors: true, mass-skip-error-on-pseudoatoms: false,…}
2. Check the warnings
3. Execute /v2/indigo/check with the following parameters:
struct
[ketcher (4).zip](https://github.com/epam/Indigo/files/6316324/ketcher.4.zip)
options: {smart-layout: true, ignore-stereochemistry-errors: true, mass-skip-error-on-pseudoatoms: false,…}
4. Check the warnings

Expected result: The number of warnings for the same structure without R-Group (steps 1,2) and with R-Group (step 3,4) is similar (only R-Group warning is added in the list of the warnings on the steps 3,4)

Actual result:
6 warnings in Remote and Standalone modes for a structure without R-Group.
4 warnings in Remote mode and 3 warnings in Standalone mode for a structure with R-Group.