now polling immediately after redirect

lib/screens/gateway/gateway_redirect.dart

@@ -38,6 +38,9 @@ class _GatewayRedirectScreenState extends State<GatewayRedirectScreen> {
     setState(() {
       redirected = true;
     });
+
+    // might as well go and poll, just in case customer doesn't come back
+    context.go("/poll");
   }
 
   @override