Bug 1070688 - [settings] unit test refactoring for new version chai.assert api

test_agent used very old version chai library version=0.5.3
in the current version=1.9.1 deepEqual take prototype into consideration
```javascript
apps/settings/test/unit/panels/keyboard_enabled_default/dialog_test.js
102: this.title, - must this.test,
```
old version chaijs incorrect deepEqual - internal for testing object equivalence used Object.keys(this.title) -> Array[0]!! and test OK for any objects!
New version used for testing for (var key in this.title) pattern
This change does not look chai-related. Can you please explain why this is needed? Thanks!