[API][FEEDBACK/POST] Status code on response 500 instead of 200 when entering valid endpoint /api/feedback/{id}/reply.

[AShoshu]

Reproducible: always.
Build found: last commit from https://github.com/ita-social-projects/TeachUA.
front 2024-01-04 d5b9ee
back 2024-01-04 7dd789
Preconditions
Postman is opened and the token(admin) is gotten.

Steps to reproduce

1. Create GET request to 'http://speak-ukrainian.eastus2.cloudapp.azure.com/dev' using endpoint/api/feedback/4/reply
2. Fill in body
   {
   "id": 0,
   "parentCommentId":4,
   "text": "Reply to comment from Postman24",
   "userId": 1
   }
   Actual result
   Ststus 500

Expected result
Status 200