core: remove BoxUpgradeRequired exception

lib/vagrant/box_collection.rb

@@ -56,8 +56,6 @@ module Vagrant
     # * BoxProviderDoesntMatch - If the given box provider doesn't match the
     #   actual box provider in the untarred box.
     # * BoxUnpackageFailure - An invalid tar file.
-    # * BoxUpgradeRequired - You're attempting to add a box when there is a
-    #   V1 box with the same name that must first be upgraded.
     #
     # Preconditions:
     # * File given in `path` must exist.

lib/vagrant/environment.rb

@@ -348,14 +348,8 @@ module Vagrant
       load_box_and_overrides = lambda do
         box = nil
         if config.vm.box
-          begin
+          box = boxes.find(
-            box = boxes.find(config.vm.box, box_formats, config.vm.box_version)
+            config.vm.box, box_formats, config.vm.box_version)
-          rescue Errors::BoxUpgradeRequired
-            # Upgrade the box if we must
-            @logger.info("Upgrading box during config load: #{config.vm.box}")
-            boxes.upgrade(config.vm.box)
-            retry
-          end
         end
 
         # If a box was found, then we attempt to load the Vagrantfile for

lib/vagrant/errors.rb

@@ -196,10 +196,6 @@ module Vagrant
       error_key(:untar_failure, "vagrant.actions.box.unpackage")
     end
 
-    class BoxUpgradeRequired < VagrantError
-      error_key(:box_upgrade_required)
-    end
-
     class BoxVerificationFailed < VagrantError
       error_key(:failed, "vagrant.actions.box.verify")
     end

templates/locales/en.yml

@@ -376,10 +376,6 @@ en:
         the provider specified. Please double-check and try again.
 
         The providers for this are: %{providers}
-      box_upgrade_required: |-
-        The box '%{name}' is still stored on disk in the Vagrant 1.0.x
-        format. This box must be upgraded in order to work properly with
-        this version of Vagrant.
       bundler_disabled: |-
         Vagrant's built-in bundler management mechanism is disabled because
         Vagrant is running in an external bundler environment. In these