HttpCLient4 adds default header that can not be easly removed. (Java does not)

**szuther** ([Bug 64010](https://bz.apache.org/bugzilla//show_bug.cgi?id=64010&redirect=false)):
httpClient4 adds

"Content-Type: application/x-www-form-urlencoded; charset=UTF-8"

(and other Header, see attached pics) for POST requests even if i don’t have specified any Header for that request,

Content-Type is unnecessary for a post without a Body.

The Server don’t except "application/x-www-form-urlencoded" as Content-Type and the Request will fail.

The Server would accept a request without Content-Type header.

The Java implementation does that not.
Its not good to have these completely different behaviour and there is no (easy?) way to send a POST request without the Content-Type Header with httpClient4.

In the attachment is the simple POST test without defined header and images of the sent request headers with java and httpclient4 implementation

Created attachment [Content-Type added.zip](https://apache.github.io/jmeter-bugzilla-attachments/10/64010/36919/Content-Type%20added.zip): Test + pics

Severity: normal
OS: