Terms and Condition required not working in register form

### Issue type

**I'm submitting a ...** (check one with "x")

* [x ] bug report
* [ ] feature request

### Issue description

**Current behavior:**
In register component, if we fill in all the fields, check the terms and condition and again uncheck it, we are able to register.
In the configuration, the forms->register->terms is already set to true

**Expected behavior:**
We should not be able to click register when the terms and conditions is not checked.

**Steps to reproduce:**
Fill in the complete register form. Click terms and condition, uncheck TnC, still you are able to register.