[ActsAsMiqSet] Fix incorrect name validation

Previously, this had existed as it is now, but it didn't seem to make a
difference to the specs with the previous `RelationshipMixin` version
of this code.

However, it seems with this change, many of the specs fail with the
following:

  32) MiqWidget multiple groups for non-self service user contents created for one timezone per group with timezone_matters = false
      Failure/Error: factory_exists?(factory) ? super : class_from_symbol(factory).create!(*args)

      ActiveRecord::RecordInvalid:
        Validation failed: MiqWidgetSet: Name has already been taken

So this form seems to be the correct one.

lib/extensions/ar_miq_set.rb

@@ -62,8 +62,10 @@ module ActsAsMiqSet
 
     validates :name,
               :presence                => true,
-              :uniqueness_when_changed => [:set_type, :userid, :group_id],
-              :if                      => proc { |c| c.class.in_my_region.exists?(:name => c.name) }
+              :uniqueness_when_changed => {
+                :scope => [:set_type, :userid, :group_id],
+                :if    => proc { |c| c.class.in_my_region.exists?(:name => c.name) }
+              }
     validates :description,
               :presence => true