Limits the number of attempts to forward the request.

	For the purpose of this limit, Squid counts all high-level request
	forwarding attempts, including any same-destination retries after
	certain persistent connection failures and any attempts to use a
	different peer. However, low-level connection reopening attempts
	(enabled using connect_retries) are not counted.
	
	See also: forward_timeout and connect_retries.