edx/edx-platform — pull request #2534 by jbau (2014-02-08 06:52:39+00:00)
Title: fix non-microsite SUBDOMAIN_BRANDING defaults

@chrisndodge we (and the vestigial edx.org hiera entry) do our `settings.COURSE_LISTINGS` like this:

```
'COURSE_LISTINGS':
'default':
- 'Medicine/SP2L/2014'
```
so if there's no microsites config, the resultant subdomain should return `'default'`. Otherwise all of the courses are displayed, instead of just those in `COURSE_LISTINGS`