def scope_for_slug_generator
      relation = super
      return relation if new_record?
      relation = relation.merge(Slug.where('sluggable_id <> ?', id))
      if friendly_id_config.uses?(:scoped)
        relation = relation.where(Slug.arel_table[:scope].eq(serialized_scope))
      end
      relation
    end
def scope_for_slug_generator
      relation = super
      return relation if new_record?
      relation = relation.merge(Slug.where('sluggable_id <> ?', id))
      if friendly_id_config.uses?(:scoped)
        relation = relation.where(Slug.arel_table[:scope].eq(serialized_scope))
      end
      relation
    end
If we're updating, don't consider historic slugs for the same record
 to be conflicts. This will allow a record to revert to a previously
 used slug.