form field: add SCROLL_ON_FOCUS

Fixes issue with choices not triggering scroll on focus.

radio/src/thirdparty/libopenui/src/form.cpp

@@ -28,6 +28,7 @@ FormField::FormField(Window* parent, const rect_t& rect,
                      LvglCreate objConstruct) :
     Window(parent, rect, windowFlags, textFlags, objConstruct)
 {
+  lv_obj_add_flag(lvobj, LV_OBJ_FLAG_SCROLL_ON_FOCUS);
 }
 
 void FormField::setEditMode(bool newEditMode)

radio/src/thirdparty/libopenui/src/form.h

@@ -84,8 +84,6 @@ class FormGroup : public Window
   class Line : public Window
   {
     FlexGridLayout *layout;
-    FormGroup *group;
-
     void construct();
 
    public: