1320 regression in resolve_unclaimed

```
Traceback (most recent call last):
  File "aspen/website.py", line 76, in handle_safely
    response = self.handle(request)
  File "aspen/website.py", line 109, in handle
    response = request.resource.respond(request)
  File "aspen/resources/dynamic_resource.py", line 47, in respond
    exec self.pages[1] in context
  File "/app/www/%username/index.html.spt", line 21, in <module>
    participant = get_participant(request, restrict=False)
  File "gittip/utils/__init__.py", line 330, in get_participant
    to = participant.resolve_unclaimed()
  File "gittip/models/participant.py", line 186, in resolve_unclaimed
    elif rec['platform'] == 'github':
TypeError: tuple indices must be integers, not unicode
```

https://app.getsentry.com/gittip/gittip/group/7545956/