Don't check Server header

Author: wchen-r7

modules/auxiliary/dos/http/ms15_034_ulonglongadd.rb

@@ -93,11 +93,6 @@ def check_host(ip)
       return
     end
 
-    if !res.headers['Server'].include?('Microsoft-IIS')
-      vprint_error("#{ip}:#{rport} - Target isn't IIS")
-      return Exploit::CheckCode::Safe
-    end
-
     res = send_request_raw({
       'uri' => uri,
       'method' => 'GET',