Should grid-manager accept only "its" certificates?

[meejah]

When adding a grid-manager certificate to a Tahoe configuration with the "tahoe admin add-grid-manager-cert" command, the identify of the certificate is not checked.

It may be desirable to check if the public-key in the certificate matches the server's public-key. It probably makes sense to WARN only (as the operator may be getting ready to change their public key .. or for some other reason .. and could edit the config by hand anyway).