What to do when akregator finds a faulty server

I went to open akregator after a while of not using it to find a message stating:

The server failed the authenticity check (cf.dipnoidtorous.cyou).
The issuer certificate of a locally looked up certificate could not be found

No certificates could be verified

How can find the feed that my server ‘cf.dip…’ is associated with and once I find it is there a way to refresh the cert or is that the server’s fault.

Should I remove the feed, and how much of a security risk is it, given that it is only a RSS feed?