captive portal: redirect using code 302

PR: https://forum.opnsense.org/index.php?topic=4477.0
(cherry picked from commit 714bd18c)

src/opnsense/service/templates/OPNsense/Captiveportal/lighttpd-zone.conf

@@ -78,6 +78,9 @@ server.bind              = "0.0.0.0"
 #### bind to port
 server.port              = {{ cp_zone_item.zoneid|int + 8000  }}
 
+## Redirect response code to use
+url.redirect-code        = 302
+
 ##
 $HTTP["host"] !~ "(.*{{cp_zone_item.redirect_host_match}}.*)" {
 	$HTTP["host"] =~ "([^:/]+)" {