api/jenkins/start sets an unnecessary cookie and has wrong content-type

[sthaha]

Here is the output of curl

curl -s -I -X POST  https://jenkins.api.prod-preview.openshift.io/api/jenkins/start

returns

HTTP/1.1 401 Unauthorized
Vary: Origin
Date: Thu, 14 Jun 2018 01:52:11 GMT
Content-Length: 94
Content-Type: text/plain; charset=utf-8
Set-Cookie: aa9519ad98a50707dccfd4122b9635ea=2d455b885365186e18f9dec390132136; path=/; HttpOnly; Secure

which sets a cookie
And the content type is text/plain instead of Content-Type: application/json