Renamed "Logger.warning" to "logger.warn"
Renamed "Logger.warning" to "logger.warn"

- app/controllers/application_controller.rb - Replaced logger.warning
  to logger.warn

Updates #847

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