A whitelist of endpoints to skip Kerberos authentication doesn't work for ResourceManager and Job History Server

Thanks to HADOOP-16527, we can add a whitelist of endpoints to skip Kerberos authentication such as /isActive, /jmx, /prom.
However, I found that ResourceManager and Job History Server doesn't repect hadoop.http.authentication.kerberos.endpoint.whitelist.

To workaround this issue for ResourceManager, set yarn.resourcemanager.webapp.delegation-token-auth-filter.enabled=true in yarn-site.xml.
However, there is no workaround for Job History Server.

This bug is caused by HttpServer2#initSpnego call without proper configurations which starts with "hadoop.http.authentication.".

I will make a PR soon.