Weird http parsing error

Not exactly sure what caused this, and it  didn't disrupt anything. This error appeared in the console while an app was running:
```
Traceback (most recent call last):
  File "..\site-packages\servepy.py", line 30, in handle
    http = _Http(self.data, self.server)
TypeError: __init__() should return None, not 'bool'
```

Looks like the constructor is doing something weird.