Un-whitelist g_playerclip_collisions

Disabling playerclip collisions causes problems on many official and unofficial maps, including getting stuck in awkward places and falling through grates. Even in defrag / CTS, some maps should not be played with clips disabled, as it enables routes the mapper deliberately blocked, as well as falling through grates. Player clips should only be disabled on maps that require it, and mapinfo settemp does not require whitelisting.