Fix for #373 - accept terms for existing user

@settinghead could you take a look at why one the tests is failing? I can't figure it out. 

Here is the test which is failing: 
https://github.com/Rise-Vision/common-header/blob/07e74a4782dc6609680ffa9555c0392ca21b6fa8/test/e2e/registration-scenarios.js#L76

The interesting part is that if I click Save button once, the modal does not close. If I click it again, it closes.

Here is where it happens in the code:
https://github.com/Rise-Vision/common-header/blob/07e74a4782dc6609680ffa9555c0392ca21b6fa8/src/js/controllers/ctr-registration-modal.js#L75