DEV: Fix lint.

DEV: Fix lint.

diff --git a/db/post_migrate/20200818084329_update_private_message_on_post_search_data.rb b/db/post_migrate/20200818084329_update_private_message_on_post_search_data.rb
index ba984a8..c15e9bc 100644
--- a/db/post_migrate/20200818084329_update_private_message_on_post_search_data.rb
+++ b/db/post_migrate/20200818084329_update_private_message_on_post_search_data.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class UpdatePrivateMessageOnPostSearchData < ActiveRecord::Migration[6.0]
   def up
     # Delete post_search_data of orphaned posts

GitHub sha: 7e414da0