Reconfigured to allow elasticsearch server transition
Reconfigured to allow elasticsearch server transition

- config/initializers/searchbox.rb - Changed elasticsearch server
  url to check ELASTICSEARCH_URL, then SEARCHBOX_URL, then the
  localhost

Updates #1522

EBWiki/EBWiki,BOWiki/BOW,EBWiki/EBWiki,BOWiki/BOW,EBWiki/EBWiki,EBWiki/EBWiki,BOWiki/BOW