AM Self-registration kba throws an error when a user inputs an answer and presses the enter key.

Bug description

In the AM self-registration process where kba (security question) is turned on. If a user enters an answer and presses the enter key they will get an "Unable to register your account - Exception intercepted". If however you click on the save button it works correctly.

How to reproduce the issue

1. Enable user self-service with kba
2. register a new user
3. when selecting security question and answer press enter to complete rather than hitting save.

Expected behaviour

Pressing enter will save the input and create the user.

Current behaviour

"Unable to register your account - Exception intercepted" is thrown and requires the registration process to start again.

Work around

When completing registration click the save button rather than hitting enter.

This however creates a bad UX as user is presented with an exception and has to re-start registration process and use the button instead of the enter key.