add content-type in Varnish/S3. placehold fix since S3 doesn't set Cache-Control and proper Content-type

main.vcl

sub vcl_fetch {
    remove beresp.http.Cache-Control;
    set beresp.http.Cache-Control = "public, max-age=31600000";
    if (req.url ~ ".jpg$") {
        set beresp.http.content-type = "image/jpeg";
    }
    if (req.url ~ ".webp$") {
        set beresp.http.content-type = "image/webp";
    }

    return(deliver);
}