Cleanup ignat99 feat

New PR from https://github.com/Ignat99/OpenBazaar/pull/1 directly into OpenBazaar:develop.
Alright, but there's another issue in that code. It's doing something like:
```python
d['foo'] = d['foo'] if 'foo' in d else ''  # where d == settings and 'foo' == 'secret'
```
All this does is ensure that `settings['secret']` has a value, though it may be `''`. If that is the intended behaviour, it can be written just:
```python
if 'secret' not in settings:
    settings['secret'] = None  # adding your comment
```