CDB3-3340 Wrong response while patching preliminaryContract in case field "preliminaryContractSigned": "true"

Precondition:
Existing procedure SPE/SPD with contract status pending

Steps to reproduce:

1. Upload preliminaryContract to contract
2. Patch contract with body

{ "preliminaryContract": { "contractNumber": "Номер попереднього договору 000000", "title": { "uk_UA": "Назва попереднього контракту" }, "description": { "uk_UA": "Опис попереднього Контракту" }, "dateSigned": {{dateSigned}} } }

3. Patch field "preliminaryContractSigned": "true"

4. Patch contract with body { "preliminaryContract": { "contractNumber": "Номер попереднього договору 000000 edited", "title": { "uk_UA": "Назва попереднього контракту edited" }, "description": { "uk_UA": "Опис попереднього Контракту edited" }, "dateSigned": {{dateSigned}} } }

5. Check response and json

Actual result:
200, but preliminaryContract does not change

Expected result:
422, because field "preliminaryContractSigned" is already "true"