Assertion fail for valid HTTP code 204

In earlier versions than 1.9 of ReadyApi the assertion for HTTP 204 worked fine. 

In this version I get failed assertion for HTTP code 204 when i response header returns "Content-Length: 0"

with error message:

"Wrong server response: responses with the 204 status code must not contain the "Content-Length" header."

I can't find anything on https://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html that supports that Content-lenghth header is not allowed.

Is there any reason why this assertions behavior have changed?

I tested in version 1.8.5 and there it works fine