Log spammed with "Could not update STH"

[davidak]

When i configure a subscriber, that can not be found, the log is spammed with this line 443 times a second!

Dec 03 11:48:57 gaming trustix[28249]: time="2022-12-03T11:48:57+01:00" level=error msg="Could not update STH" error="Couldn't find client for tag: e0f263745e4e3ab07ab5275b00b44f594e0b6d2bd35892a8ebd10a7f86322eb7" logID=e0f263745e4e3ab07ab5275b00b44f594e0b6d2bd35892a8ebd10a7f86322eb7

    subscribers = [
      # local
      {
        protocol = "nix";
        publicKey = {
          type = "ed25519";
          key = "APAu/WvYTnCQSIg+5OzWKC/D+JzWFJZmvNsPPBbfhcQ=";
        };
      }
      # demo.trustix.dev
#      {
#        protocol = "nix";
#        publicKey = {
#          type = "ed25519";
#          key = "2uy8gNIOYEewTiV7iB7cUxBGpXxQtdlFepFoRvJTCJo=";
#        };
#      }
    ];

(the commented out part)

Similar to #34