MINOR: log: fix "http-send-name-header" ignore warning message

Warning message to indicate that the "http-send-name-header" option is
ignored for backend in "mode log" was referenced using its internal
struct wording instead of public name (as seen in the documentation).

Let's fix that.

It may be backported with c7783fb ("MINOR: log/backend: prevent
"http-send-name-header" use with LOG mode") in 2.9.

(cherry picked from commit e5ccfda)
Signed-off-by: Christopher Faulet <[email protected]>

Author: Darlelet

src/log.c

@@ -1199,7 +1199,7 @@ static int _postcheck_log_backend_compat(struct proxy *be)
 		free_stick_rules(&be->sticking_rules);
 	}
 	if (isttest(be->server_id_hdr_name)) {
-		ha_warning("Cannot set \"server_id_hdr_name\" with 'mode log' in %s '%s'. It will be ignored.\n",
+		ha_warning("Cannot set \"http-send-name-header\" with 'mode log' in %s '%s'. It will be ignored.\n",
 			   proxy_type_str(be), be->id);
 
 		err_code |= ERR_WARN;