trafficserver v9.x close connection instead of using content-length header

[esmq2092]

i know there are three ways that http1.1 can use to tell the size of message body,

• Connection: close
• Content-Length: xxx
• Transfer-Encoding: chunked

after upgrading to trafficserver v9.2.5,

in http1.1 scenario，chunk encoding is disabled while compress plugin is loaded，
trafficserver always actively close the connection，by doing so it can tell the size of message body without return Content-Length header，

for previous versions, at least v8.1.11，trafficserver prefer to use keep-alive connection with content-length header，and i think that is the more suitable way。

[esmq2092]

there are some more i found，when chunk enabled，

for trafficserver v7.x/v8.x，it only return chunk encoding for the first compress-request，the subsequent requests are not chunk, and return Content-Length header。

for trafficserver v9.x，it always return chunk encoding for compress-requests and without Content-Length header。