settings: handle a `undefined` scroller (BJS1)

Fixes #3824

apps/setting/ChangeLog

@@ -86,3 +86,4 @@ of 'Select Clock'
 0.75: Restore previous menu's scroll positions
 0.76: Add altitude calibration menu (and update README after menu changed)
 0.77: Save altitude calibration when user exits via reset
+0.78: Fix menu scroll restore on BangleJS1

apps/setting/metadata.json

@@ -1,7 +1,7 @@
 {
   "id": "setting",
   "name": "Settings",
-  "version": "0.77",
+  "version": "0.78",
   "description": "A menu for setting up Bangle.js",
   "icon": "settings.png",
   "tags": "tool,system",

apps/setting/settings.js

@@ -27,7 +27,8 @@ function pushMenu(menu) {
 function restoreMenu(menu) {
   // equivalent to pushMenu(null); popMenu(menu);
   if(!menu[""]) menu[""] = {};
-  menu[""].scroll = menuScroller.scroll;
+  if(menuScroller) // may be undefined on BangleJS1
+    menu[""].scroll = menuScroller.scroll;
   menuScroller = E.showMenu(menu).scroller;
 }