Changes [0e57c70baf11a7f0211f78a5282f8ba26fbc17b4] by Pratik Naik in 2-3-stable doesn't pass the tests

Hi,

The commit Don't try yo load record from db... is the same that the commit added to the master branch Don't try to load record from db... master but in 2-3-stable branch the test added doesn't pass..

Here the output:

1) Failure: test_preloading_empty_polymorphic_parent(EagerAssociationTest)

[./test/cases/../../lib/active_record/test_case.rb:31:in `assert_queries'
 ./test/cases/associations/eager_test.rb:837:in `test_preloading_empty_polymorphic_parent'
 ./test/cases/../../../activesupport/lib/active_support/testing/setup_and_teardown.rb:62:in `__send__'
 ./test/cases/../../../activesupport/lib/active_support/testing/setup_and_teardown.rb:62:in `run']:

0 instead of 2 queries were executed.
expected but was
.

I don't know how the preload method works but maybe should be enough with this patch.