When this is 'on', a request will not go through the
	helper if all helpers are busy.  If this is 'off'
	and the helper queue grows too large, Squid will exit
	with a FATAL error and ask you to increase the number of
	helpers.  You should only enable this if the helperss
	are not critical to your caching system.  If you use
	helpers for critical caching components, and you enable this 
	option,	users may not get objects from cache.