Ember was throwing this error preventing the reorder categories feature
from working:
```
access theidproperty (of <(unknown):ember1803>). ... the object in question
is a special kind of Ember object (a proxy). Therefore, it is still necessary
to use.get('id')in this case.
```
So I updated it to use the `get` method
https://api.emberjs.com/ember/3.14/functions/@ember%2Fobject/get
Follow up to: 6e5fedb312
Blake Erickson
f921909595