Change older Paperclip database migrations for consistency (#30204)

db/migrate/20160312193225_add_attachment_header_to_accounts.rb

@@ -3,7 +3,11 @@
 class AddAttachmentHeaderToAccounts < ActiveRecord::Migration[4.2]
   def self.up
     change_table :accounts do |t|
-      t.attachment :header
+      # The following corresponds to `t.attachment :header` in an older version of Paperclip
+      t.string :header_file_name
+      t.string :header_content_type
+      t.integer :header_file_size
+      t.datetime :header_updated_at
     end
   end