Make `truncate_tables` to bulk statements

Before:

```
   (16.4ms)  TRUNCATE TABLE `author_addresses`
   (20.5ms)  TRUNCATE TABLE `authors`
   (19.4ms)  TRUNCATE TABLE `posts`
```

After:

```
  Truncate Tables (19.5ms)  TRUNCATE TABLE `author_addresses`;
TRUNCATE TABLE `authors`;
TRUNCATE TABLE `posts`
```

1 files changed, 1 insertions, 3 deletions

diff --git a/activerecord/lib/active_record/tasks/database_tasks.rb b/activerecord/lib/active_record/tasks/database_tasks.rb
index 5a46003732..f18990cc5b 100644
--- a/activerecord/lib/active_record/tasks/database_tasks.rb
+++ b/activerecord/lib/active_record/tasks/database_tasks.rb
@@ -190,9 +190,7 @@ module ActiveRecord
             ActiveRecord::Base.internal_metadata_table_name
           ]
 
-          ActiveRecord::Base.connection.disable_referential_integrity do
-            ActiveRecord::Base.connection.truncate_tables(*table_names)
-          end unless table_names.empty?
+          ActiveRecord::Base.connection.truncate_tables(*table_names) unless table_names.empty?
         end
       end
       private :truncate_tables