Fix a test that assumes that defined?(ActiveRecord) == defined?(ActiveRecord::Base)

railties/test/application/initializers/frameworks_test.rb

@@ -91,7 +91,7 @@ module ApplicationTests
     test "database middleware doesn't initialize when activerecord is not in frameworks" do
       use_frameworks []
       require "#{app_path}/config/environment"
-      assert_nil defined?(ActiveRecord)
+      assert_nil defined?(ActiveRecord::Base)
     end
   end
 end