Exactly, I changed test because this tested behavior was wrong - new test tests cross new intepretation. (In issue was problem, that true in key is replace to special keyword, and this test is example of this behavior)

I agree with @rostenkowski, that this change isn't BC break, but in some cases it can cause problems like:
existing working configuration:
```
parameters:
 "true": foo
 true: foo2
```

will result to fail because of duplicate key "true"