i2pd: repo.i2pd.xyz problem

# apt-get update
......
Err https://repo.i2pd.xyz jessie/main amd64 Packages
  HttpError400
Fetched 155 kB in 12s (12.8 kB/s)
W: Failed to fetch https://repo.i2pd.xyz/debian/dists/jessie/main/binary-amd64/Packages  HttpError400

E: Some index files failed to download. They have been ignored, or old ones used instead.

#apt-get install i2pd
......
WARNING: The following packages cannot be authenticated!
  i2pd
Install these packages without verification? [y/N]