send proper 404 for incomplete/misconfigured feeds
send proper 404 for incomplete/misconfigured feeds

katrinleinweber/podlove-publisher,katrinleinweber/podlove-publisher,podlove/podlove-publisher,noplanman/podlove-publisher,katrinleinweber/podlove-publisher,katrinleinweber/podlove-publisher,podlove/podlove-publisher,podlove/podlove-publisher,noplanman/podlove-publisher,noplanman/podlove-publisher,podlove/podlove-publisher,katrinleinweber/podlove-publisher,podlove/podlove-publisher,noplanman/podlove-publisher,noplanman/podlove-publisher,podlove/podlove-publisher