Kibana version:
5.0.0-alpha5

Elasticsearch version:
5.0.0-alpha5

Server OS version:
OSX

Browser version:
Chrome( 52.0.2743.82) and Safari (9.1.1)

Browser OS version:
OSX

Original install method (e.g. download page, yum, from source, etc.):
download page

Description of the problem including expected versus actual behavior:
When running in Console:

GET _search
{
  "query": {
    "match_all": {}
  }
}

it generates the following POST request:

POST /_search 
…
Content-Type: application/x-www-form-urlencoded; charset=UTF-8
Host: localhost:9200
Connection: close
…

{ "query": {   "match_all": {}  }}

The Content-Type specifies that the attachment is a form, but instead it's a JSON object.

Steps to reproduce:

1. run ngrep on localhost to get all the http traffic
2. start Console and run the default command
3. check the generated POST request.