Merge branch 'fix_element_destroy' into 'master'

Fix bug in LuaUi::Element::destroy() that sometimes leads to an infinite loop on UI cleanup

See merge request OpenMW/openmw!3033

components/lua_ui/element.cpp

@@ -216,12 +216,12 @@ namespace LuaUi
 
     void Element::destroy()
     {
+        sAllElements.erase(this);
         if (!mRoot)
             return;
         destroyWidget(mRoot);
         mRoot = nullptr;
         mLayout = sol::make_object(mLayout.lua_state(), sol::nil);
-        sAllElements.erase(this);
     }
 
     void Element::attachToWidget(WidgetExtension* w)