Fixed a language-related error when doing a "PageFinder::getQuery" 

Hi Ryan,

This is a proposed fix for a PHP error that occurs when the current user has no language field, for example in the following case:

1.  call wire("session")->login(...)
2.  search for a given page in the sites pages,
3. redirect the session to this page.

If the logged-in user has no defined language field, there is a php error during step 2 (like: calling "isDefault() on a non object).