Revert PR#5001 "removed unuseful require for reply as we are not using require model"

This reverts commit 7381596e.

activerecord/test/cases/attribute_methods_test.rb

@@ -8,6 +8,7 @@
 require 'models/topic'
 require 'models/company'
 require 'models/category'
+require 'models/reply'
 require 'models/contact'
 require 'models/keyboard'
 

activerecord/test/cases/fixtures_test.rb

@@ -16,6 +16,7 @@
 require 'models/pirate'
 require 'models/post'
 require 'models/randomly_named_c1'
+require 'models/reply'
 require 'models/ship'
 require 'models/task'
 require 'models/topic'

activerecord/test/cases/identity_map_test.rb

 require "cases/helper"
+
 require 'models/developer'
 require 'models/project'
 require 'models/company'
 require 'models/topic'
+require 'models/reply'
 require 'models/computer'
 require 'models/customer'
 require 'models/order'

activerecord/test/cases/named_scope_test.rb

@@ -2,6 +2,7 @@
 require 'models/post'
 require 'models/topic'
 require 'models/comment'
+require 'models/reply'
 require 'models/author'
 require 'models/developer'