Is it a warning from certbot? I'm guessing it's just what it says: that it can't tell if the certificate is revoked or not since there's no OCSP URL in there anymore.
Wouldn't shock me if newer versions of certbot expected it and don't phrase it in an alarming way. 1.7 is several major versions old by now (they're up to 4.0 now); so you might want to upgrade. This may involve uninstalling the version your OS's built-in package manager uses and installing it via a different way.
Or you can just ignore it, is there really a problem you're running into or is it just a scary warning?