basic_functions: update error_log documentation [skip ci] (#17828)

Sending to a TCP/IP address is not an option anymore, and it hasn't been since
before the file was created in this repo in 1999 (257de2b). Based on
php/doc-en@d522d13 it appears that this
feature was part of PHP 3 and removed before PHP 4. I tried to track down the
original code to find when it was actually removed but wasn't able to find a
PHP 3 repository.

Author: DanielEScherzer

ext/standard/basic_functions.c

@@ -1336,7 +1336,7 @@ PHP_FUNCTION(get_cfg_var)
 error options:
 	0 = send to php_error_log (uses syslog or file depending on ini setting)
 	1 = send via email to 3rd parameter 4th option = additional headers
-	2 = send via tcp/ip to 3rd parameter (name or ip:port)
+	2 = no longer an option
 	3 = save to file in 3rd parameter
 	4 = send to SAPI logger directly
 */