OpenTSDB: Fixed a bug that sent the size of the compressed file as a content length for the uncompressed contents. (https://rbcommons.com/s/pepperdata/r/3421)

The following curl command saved a portion of uncompressed query results when they do not support gzip.
curl 'http://localhost:14249/api/query?start=2014/02/04-12:00:00&end=2014/02/04-13:00:01&m=sum:iw-1m:task.task.count' -o output.partial

The following curl command saved the full uncompressed file.
curl --compressed 'http://localhost:14249/api/query?start=2014/02/04-12:00:00&end=2014/02/04-13:00:01&m=sum:iw-1m:task.task.count' -o output.full

**** BUG ***
$ curl 'http://localhost:14249/api/query?start=2014/02/04-12:00:00&end=2014/02/04-13:00:01&m=sum:iw-1m:task.task.count' -o output.partial -v
> GET /api/query?start=2014/02/04-12:00:00&end=2014/02/04-13:00:01&m=sum:iw-1m:task.task.count HTTP/1.1
> User-Agent: curl/7.30.0
> Host: localhost:14249
> Accept: */*
>
< HTTP/1.1 200 OK
< Content-Type: text/plain
< Age: 526
< Cache-Control: max-age=86400
< Content-Length: 3046
<

**** After the fix ***
$ curl 'http://localhost:14249/api/query?start=2014/02/04-12:00:00&end=2014/02/04-13:00:01&m=sum:iw-1m:task.task.count' -o output.partial -v
> GET /api/query?start=2014/02/04-12:00:00&end=2014/02/04-13:00:01&m=sum:iw-1m:task.task.count HTTP/1.1
> User-Agent: curl/7.30.0
> Host: localhost:14249
> Accept: */*
>
< HTTP/1.1 200 OK
< Content-Type: text/plain
< Age: 900
< Cache-Control: max-age=86400
< Content-Length: 19771
<