Avoid getting redefined method warning

Warning:

  ~/projects/rails/activerecord/lib/active_record/railtie.rb:140: warning: method redefined; discarding old extend_message
  ~/projects/rails/activerecord/lib/active_record/errors.rb:104: warning: previous definition of extend_message was here

activerecord/lib/active_record/railtie.rb

@@ -137,6 +137,7 @@ class Railtie < Rails::Railtie # :nodoc:
       ActiveSupport.on_load(:active_record) do
 
         class ActiveRecord::NoDatabaseError
+          remove_possible_method :extend_message
           def extend_message(message)
             message << "Run `$ bin/rake db:create db:migrate` to create your database"
             message