Fix defect with invalid delegation of #execute in updater instance.

Changes:
- Fix defect.
- Fix specs accordingly.

Task 10689
Merge pull request #8 from 10571_fix_defect_with_invalid_delegation_of_execute

* origin/10571_fix_defect_with_invalid_delegation_of_execute:
  Fix defect with invalid delegation of #execute in updater instance.

Task 10571