Reqparse cannot parse_args() while flask run in venv

[tanjeetsarkar]

1. Using Api
2. in extended Resourse class.
3. In any kind of request (post,get,...)
4. add_argument("name", type=str, required=true, help=' ') runs properly creating object.

once these steps are done parse_args() doesn't work and we get no error but with a response

{'message': 'request header type not application/json'}

This only happens while flask run in venv. when venv deactivated it runs properly.

[davidism]

Duplicate of #936