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, these low-level attempts are not counted:
	* connection reopening attempts (enabled using connect_retries)
	* unfinished Happy Eyeballs connection attempts (prevented by setting
	  happy_eyeballs_connect_limit to 0)

	See also: forward_timeout and connect_retries.