system: fix typo in default far gw default setup

Kindly pointed out by a generous tester.  Thank you.

(cherry picked from commit 0ce997d0)
(cherry picked from commit 29153230)

src/etc/inc/system.inc

@@ -590,8 +590,8 @@ function system_routing_configure($interface = '')
         log_error("ROUTING: setting IPv4 default route to {$gatewayip}");
         mwexecf('/sbin/route delete -inet %s', 'default');
         if ($fargw) {
-            mwexecf('/sbin/route delete -inet %s -interface %s', array($gatewayip, $interfacegw));
-            mwexecf('/sbin/route add -inet %s -interface %s', array($gatewayip, $interfacegw));
+            mwexecf('/sbin/route delete -inet %s -interface %s', array($gatewayip, $defaultif));
+            mwexecf('/sbin/route add -inet %s -interface %s', array($gatewayip, $defaultif));
         }
         mwexecf('/sbin/route add -inet %s %s', array('default', $gatewayip));
     }
@@ -605,8 +605,8 @@ function system_routing_configure($interface = '')
         log_error("ROUTING: setting IPv6 default route to {$gatewayipv6}");
         mwexecf('/sbin/route delete -inet6 %s %s', array('default', $gatewayipv6));
         if ($fargw) {
-            mwexecf('/sbin/route delete -inet6 %s -interface %s', array($gatewayipv6, $interfacegwv6));
-            mwexecf('/sbin/route add -inet6 %s -interface %s', array($gatewayipv6, $interfacegwv6));
+            mwexecf('/sbin/route delete -inet6 %s -interface %s', array($gatewayipv6, $defaultifv6));
+            mwexecf('/sbin/route add -inet6 %s -interface %s', array($gatewayipv6, $defaultifv6));
         }
         mwexecf('/sbin/route add -inet6 %s %s', array('default', $gatewayipv6));
     }
@@ -764,8 +764,8 @@ function system_staticroutes_configure($interface = '', $update_dns = false)
                     if (is_ipaddr($gatewayip)) {
                         mwexec("/sbin/route delete".$cmd . escapeshellarg($gatewayip));
                         if ($fargw) {
-                            mwexecf('/sbin/route delete %s %s -interface %s', array($inet, $ip, $interfacegw));
-                            mwexecf('/sbin/route add %s %s -interface %s', array($inet, $ip, $interfacegw));
+                            mwexecf('/sbin/route delete %s %s -interface %s', array($inet, $gatewayip, $interfacegw));
+                            mwexecf('/sbin/route add %s %s -interface %s', array($inet, $gatewayip, $interfacegw));
                         }
                         mwexec("/sbin/route add".$cmd . escapeshellarg($gatewayip));
                     } elseif (!empty($interfacegw)) {