[tor-relays] Key expired problem - Ubuntu 12.04 LTS

[kingqueen]

I'm experiencing difficulties running apt-get update as it complaints
that the repository's key is out of date. Here's the error:

W: A error occurred during the signature verification. The repository is not updated and the previous index files will be used. GPG error: http://deb.torproject.org precise Release: The following signatures were invalid: KEYEXPIRED 1409325681 KEYEXPIRED 1409325681 KEYEXPIRED 1409325681 KEYEXPIRED 1409325681

W: Failed to fetch http://deb.torproject.org/torproject.org/dists/precise/Release

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

When I set the relay up, I used Option Two on this page
https://www.torproject.org/docs/debian to install tor and
deb.torproject.org-keyring . Updates worked for 10 weeks or so and now
don't. I've tried going through the same processes again, to no avail.

Any assistance very gratefully received.