Cannot get value

### Version of x-select:
3.1.1
### Ember Version / Ember CLI Version:
2.18

### Actual Behavior
value is not set

### Ember Twiddle / Example repo / Failing test:
https://ember-twiddle.com/f18762866b47e35b118d6a857642fc31?openFiles=templates.application.hbs%2C

Start with the linked Ember Twiddle, using the reported x-select 3.1.1 and Ember 2.18 versions, and inspect templates.application.hbs as indicated by the URL. Reproduce the case where the value is not set, then trace the relevant component behavior. Done means the value is set as expected in the reported example.

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