Move validation message to locales

plugins/kernel_v2/config/vm.rb

@@ -815,7 +815,8 @@ module VagrantPlugins
         disk_names = @disks.map { |d| d.name }
         duplicate_names = disk_names.detect{ |d| disk_names.count(d) > 1 }
         if duplicate_names && duplicate_names.size
-          errors << "Duplicate disk names found: #{duplicate_names}. Please use unique names"
+          errors << I18n.t("vagrant.config.vm.multiple_disk_names_error",
+                           name: duplicate_names)
         end
 
         @disks.each do |d|

templates/locales/en.yml

@@ -1905,6 +1905,8 @@ en:
           Ignoring provider config for validation...
         multiple_primary_disks_error: |-
           There are more than one primary disks defined for guest '%{name}'. Please ensure that only one disk has been defined as a primary disk.
+        multiple_disk_names_error: |-
+          Duplicate disk names defined: '%{name}'. Disk names must be unique.
         name_invalid: |-
           The sub-VM name '%{name}' is invalid. Please don't use special characters.
         network_ip_ends_in_one: |-