400 Response does not list "Terms and Conditions is not of type 'boolean'" message.

When registering a new user, if Terms and condition is not filled then we see expected error message "terms_and_conditions_checked": "'' is not of type 'boolean'". But this message is not listed under 400 Responses.

**To Reproduce**

Steps to reproduce the behavior:

1. Go to 'User-Register'.
2. {
"name": "testub",
"username": "testub",
"password": "testub123",
"email": "tajof47157@coalamails.com",
"terms_and_conditions_checked":"",
"need_mentoring":true,
"available_to_mentor":true
}
3. Click on 'Execute'.
4. Scroll down to 'Response'.
5.

**Expected behavior**
All the error messages should be listed under the 400 error messages.

**Desktop (please complete the following information):**
- OS: Windows 10
- Browser Chrome

**Additional context**
This is showing the same error message when "need_mentoring" and "available_to_mentor" is not filled.