Remove VirtualBox Hostname middleware

plugins/providers/virtualbox/action/host_name.rb

@@ -1,21 +0,0 @@
-module VagrantPlugins
-  module ProviderVirtualBox
-    module Action
-      class HostName
-        def initialize(app, env)
-          @app = app
-        end
-
-        def call(env)
-          @app.call(env)
-
-          host_name = env[:machine].config.vm.hostname
-          if !host_name.nil?
-            env[:ui].info I18n.t("vagrant.actions.vm.host_name.setting")
-            env[:machine].guest.change_host_name(host_name)
-          end
-        end
-      end
-    end
-  end
-end