Fixing a server descriptor bug where checking our fingerprint didn't honor our
skip_crypto_validation argument. This bug made it difficult to create
descriptors with a preset fingerprint...

  >>> RelayDescriptor.create({'fingerprint': '4F0C 867D F0EF 6816 0568 C826 838F 482C EA7C FE44'})
  ...
  ValueError: Fingerprint does not match the hash of our signing key
  (fingerprint: 4f0c867df0ef68160568c826838f482cea7cfe44, signing key hash:
  8f54270a36526ab35895d5f899b6ae4059faecb3)