Favicon fetch drops a user-set Host header #2700

httpx -favicon clones the page request and then replaces its Host with the favicon URL host. A virtual host selected with -H "Host: ..." or a vhost,ip input is therefore requested as the default host whenever the icon is on that same machine, so the hash is missing or belongs to the wrong site. An icon on another hostname, such as a redirect target or a CDN, should still be requested with that hostname.