Fix KeyError: 'container' when scraping cover photo metadata

[mikotokuroko]

Problem

ghunt email <address> --json ... crashes with a KeyError: 'container' during the person scrape step:

File "ghunt/parsers/people.py", line 164, in _scrape
    self.coverPhotos[cover_photo_data["metadata"]["container"]] = person_cover_photo
KeyError: 'container'

This happens in _scrape() when Google's People API returns cover photo metadata without a container field. The field isn't always present depending on the account's privacy settings / whether a custom cover photo is set, so indexing into it directly with [...] crashes instead of degrading gracefully.

---

Fix

Use .get() to safely check for the container key, and skip adding the cover photo entry if it's missing rather than crashing the whole lookup:

container = cover_photo_data["metadata"].get("container")
if container is not None:
    self.coverPhotos[container] = person_cover_photo