Remove server banner when block the robots

ok i placed the noserver option before the content ... now it is working

when HTTP_REQUEST { 
      if { .... }{   
            some actions.... 

     } elseif {[string tolower [HTTP::uri]] equals "/robots.txt"}{

             HTTP::respond 200 content "User-agent: *\r\nDisallow: /" noserver "Content-Type" "text/plain"
             log local0. "Attempt by [IP::client_addr] crawling our site" 
      }
}

a quick test:

[root@f5vm01:] ~  openssl s_client -quiet -connect f5vmvs01.local:443
...
GET /robots.txt HTTP/1.1
Host: f5vmvs01.local

HTTP/1.0 200 OK
Content-Type: text/plain
Connection: Keep-Alive
Content-Length: 26

User-agent: *
Disallow: /