[Bugfix - LOW] Fixed an issue in which plugin page URLs don't respect the site's URLs structure

For some reason, not sure why, it seems they're using the `qa_path_to_root()` explicitly. I think this is a simple bug but maybe I'm missing something here.

In simple terms, if the URL structure is this one `/index.php?qa=123&qa_1=why-do-birds-sing` the current function returns `http://site.com/the-url-here`. The proposed one would return `http://site.com/index.php?qa=the-url-here`.