Make trailing-slash-on-void-elements message not depend on profile code

[sideshowbarker]

We probably want to remove errorProfileMap and all its related stuff in the tokenizer code, since there’s no evidence it’s used by anybody anywhere in any consumer code except for what’s in the checker code, and there’s no evidence that anybody’s using that feature (which has no associated UI and but instead depends on passing in a query param).

Given all that, it seems imprudent to yoke the trailing-slash-on-void-elements message behavior to that likely-to-be-removed errorProfileMap code.