{cache_media_youtube_status} may not exist when clearing cache

The {cache_media_youtube_status} table is created by a hook_update_N() implementation, and also returned in a hook_flush_caches() implementation. However, when database upgrades happen (at least when using Drush), cache is cleared before the hook_update_N() implementations are called. This means that, when upgrading from a version of the module before the table exists, Drupal will try to truncate the table before it exists.