caddy: update hash

this is not sustainable

modules/gateway.nix

···
         enable = true;
         package = pkgs.caddy.withPlugins {
           plugins = [ "github.com/caddy-dns/cloudflare@v0.2.1" ];
-          hash = "sha256-j+xUy8OAjEo+bdMOkQ1kVqDnEkzKGTBIbMDVL7YDwDY=";
+          hash = "sha256-XwZ0Hkeh2FpQL/fInaSq+/3rCLmQRVvwBM0Y1G1FZNU=";
         };
         enableReload = true;
         globalConfig = ''