url_to_postid does not work at MS install in context of another blog when $wp_rewrite->use_verbose_page_rules differs

[david.binda]

In a multisite installation, where there are blogs with mixed permastruct of some have the $wp_rewrite->use_verbose_page_rules set to true and some to false, the url_to_postid fails to find a post, since it's queried as a page, due to a falsey check.

As the rewrites rules are untouched upon switch_to_blog action and as the url_to_postid function works directly with the rewrite_rules option (via `WP_Rewrite::wp_rewrite_rules()` function ), IMHO the best way to fix such a case would be to not rely on the property, but perform the same check as when the use_verbose_page_rules property is being set (see the attached patch).