When a jenkins api is called without authentication info, jenkins return 403 error code. According to RFC 2616, jenkins should return 401.

This bug makes my Jira webhook not working.  

My Jira webhook is created like this:    http://username:password@jenkins.xxxxx.com/view/ci-megalodon-master/job/provision2/buildWithParameters.   

Jira first call this webhook without authentication info, if webhook return 401, Jira will then call webwook with authentication info.

But as jenkins return 403, the Jira webhook just failed.

Reference about 401 &403:

https://tools.ietf.org/html/rfc2616#section-10.4.2

http://www.dirv.me/blog/2011/07/18/understanding-403-forbidden/index.html