Detect Content-Length and Transfer-Encoding Conflict

[mnot]

[mnot]

   If a message is received with both a Transfer-Encoding header
   field and a Content-Length header field, the Transfer-Encoding
   overrides the Content-Length.  Such a message might indicate an
   attempt to perform request or response smuggling (bypass of
   security-related checks on message routing or content) and thus
   ought to be handled as an error.  The provided Content-Length
   MUST be removed, prior to forwarding the message downstream, or
   replaced with the real message-body length after the transfer-
   coding is decoded.