Revert "Settings: load app settings in their own scope"

> Actually eval('('+appSettings+')') is significantly worse I'm afraid.
>
> Basically, if you do Storage.read you get a pointer to external memory
> Any functions have their code kept in that memory so it saves loads of
> RAM. The second you append to the string it has to copy everything to
> RAM - so now every function ends up in RAM, not Flash :(

This reverts commit c135c70f

apps/setting/settings.js

@@ -323,7 +323,7 @@ function showAppSettings(app) {
     return showError('Missing settings');
   }
   try {
-    appSettings = eval('('+appSettings+')');
+    appSettings = eval(appSettings);
   } catch (e) {
     console.log(`${app.name} settings error:`, e)
     return showError('Error in settings');