console: fix access test of gateways array

src/etc/rc.initial.setlanip

@@ -196,7 +196,7 @@ function next_unused_gateway_name($interface)
     global $g, $config;
     $new_name = "GW_" . strtoupper($interface);
 
-    if (!is_array($config['gateways']['gateway_item'])) {
+    if (!isset($config['gateways']['gateway_item'])) {
         return $new_name;
     }
     $count = 1;
@@ -219,7 +219,8 @@ function next_unused_gateway_name($interface)
 function add_gateway_to_config($interface, $gatewayip, $inet_type)
 {
     global $g, $config, $dry_run;
-    if (!is_array($config['gateways']['gateway_item'])) {
+
+    if (!isset($config['gateways']['gateway_item'])) {
         $config['gateways']['gateway_item'] = array();
     }
     $a_gateways = &$config['gateways']['gateway_item'];