Strict=True Returns "amazonaws.com" as an eTLD

The following code:

```#!/usr/bin/env python3
from publicsuffix2 import PublicSuffixList

psl = PublicSuffixList(idna=True)
print(psl.get_public_suffix('snack.amazonaws.com',strict=True))
```

returns `snack.amazonaws.com` when it should return `amazonaws.com`.