Bug 1069150 - [sms] unittest threads_test.js incorrect using assert.include for testing existing object propertyng

```javascript
253: assert.include(Thread.prototype, 'drafts'); 
```
assert.include - test inclusion of an object in another. Works for strings and Arrays, for other do nothing!! You may set any string - draft_draft for example and test OK!
can you use assert.property instead? For the sake of consistency with other code...