UDP scrape returns invalid info hashes

[feross]

Expected:

{ announce: 'udp://127.0.0.1:57047',
  infoHash: '4cb67059ed6bd08362da625b3ae77f6f4a075705',
  complete: 0,
  incomplete: 0,
  downloaded: 0 }

Actual:

{ announce: 'udp://127.0.0.1:57047',
  infoHash: '4',
  complete: 0,
  downloaded: 0,
  incomplete: 0 }