FIX: ensure consistency should handle cases where a topic trashed

Followup to c05b6170

app/models/category.rb

@@ -679,7 +679,7 @@ class Category < ActiveRecord::Base
     SQL
 
     DB.query_single(sql).each do |id|
-      Topic.find(id).destroy!
+      Topic.with_deleted.find_by(id: id).destroy!
     end
 
     sql = <<~SQL

spec/models/category_spec.rb

@@ -898,6 +898,9 @@ describe Category do
       uncategorized.create_category_definition
       uncategorized.topic.posts.first.destroy!
 
+      # make stuff extra broken
+      uncategorized.topic.trash!
+
       category = Fabricate(:category)
       category_destroyed = Fabricate(:category)
       category_trashed = Fabricate(:category)