Prevent crashes during migration in certain PostgreSQL configurations

Author: wojciechka

Rakefile

@@ -5,3 +5,8 @@
 require File.expand_path('../config/application', __FILE__)
 
 Discourse::Application.load_tasks
+
+# this prevents crashes when migrating a database in production in certain
+# PostgreSQL configuations when trying to create structure.sql
+Rake::Task["db:structure:dump"].clear if Rails.env.production?
+