WP `redirect_canonical()` bug workaround. See websharks/quick-cache#209

Moves the `\quick_cache\advanced_cache::$is_a_wp_content_type` checks into `template_redirect` at priority `11`; which comes after the `redirect_canonical` hook fires. This is a good workaround for the bug reported in websharks/quick-cache#209 while we await a full solution from the WP dev team.

In short, we don't call upon `is_front_page()` until after `redirect_canonical()` has already done its thing. This doesn't correct the bug in WP, but it should keep Quick Cache from exposing it.