Change older Paperclip database migrations for consistency (#30204)

db/migrate/20170913000752_create_site_uploads.rb

@@ -4,7 +4,13 @@ class CreateSiteUploads < ActiveRecord::Migration[5.1]
   def change
     create_table :site_uploads do |t|
       t.string :var, default: '', null: false, index: { unique: true }
-      t.attachment :file
+
+      # The following corresponds to `t.attachment :file` in an older version of Paperclip
+      t.string :file_file_name
+      t.string :file_content_type
+      t.integer :file_file_size
+      t.datetime :file_updated_at
+
       t.json :meta
       t.timestamps
     end