Kibana version: 4.5.3

Elasticsearch version: Version: 2.3.4, Build: e455fd0/2016-06-30T11:24:31Z, JVM: 1.8.0_91

Server OS version: LXD Ubuntu 16.04 4.4.0-31-generic

Browser version: Chrome

Browser OS version: Ubuntu 16.04 Desktop

Original install method (e.g. download page, yum, from source, etc.): Linux 64-bit version tar.gz from download page

Description of the problem including expected versus actual behavior: unable to set server.host: _site_ as possible with Elasticsearch's network.host: _site_ option

Steps to reproduce:

1. Launch LXD container
2. Download & unpack Kibana
3. Config kibana.yml
4. Launch Kibana

Errors in browser console (if relevant):

root@neutron-kibana:~# su - kibana
No directory, logging in with HOME=/
$ kibana
FATAL { [ValidationError: child "server" fails because [child "host" fails because ["host" must be a valid hostname]]]
  name: 'ValidationError',
  details:
   [ { message: '"host" must be a valid hostname',
       path: 'server.host',
       type: 'string.hostname',
       context: [Object] } ],
  _object:
   { pkg:
      { version: '4.5.3',
        buildNum: 9910,
        buildSha: 'f40c28c2644639c34c2845c432c81be3c0c7955e' },
     pid: { exclusive: false },
     server: { port: 80, host: '_site_' } },
  annotate: [Function] }

Describe the feature:

Allow _site_ option to be set for server.host in kibana.yml