Revert "Try to provoke a python2.6 bug to prove we've fixed it"

The test template output is compared against an expected output.  Since
hostvars contains information specific to the host it runs on we can't
test the python2.6 bug this way.

This reverts commit af4d6105a5.

test/integration/roles/test_filters/templates/foo.j2

@@ -17,9 +17,6 @@ Dumping the same structure to YAML, but don't pretty print
 
 {{ some_structure | to_yaml }}
 
-Dumping hostvars to JSON (exercising a python-2.6 bug)
-{{ hostvars | to_nice_json }}
-
 From a recorded task, the changed, failed, success, and skipped
 filters are shortcuts to ask if those tasks produced changes, failed,
 succeeded, or skipped (as one might guess).