makeWebRequest without content-type header field for http DELETE?

Is it somehow possible to not set the content-type header fied?
It's filled with a default value dependent on the http type (POST, DELETE...). But the default value causes error on server side.

I have a API , where DELETE is used with a JSON http body (to define the entry).

Sending a DELETE with a body is only possible in ConnectIQ if content type JSON is set in the header field. If not, no body is attached.
But the server doesn't allow a DELETE with content-type application/json. Only application/text or absence of this header field is allowed.

Can I prevent the default ConnectIQ content-type? Can I overwrite this field with "application/text" or dont add to the header at all?