Fix Tree's 'scroll_to_item()' not working correctly on some cases

(cherry picked from commit 144a4cc39f037b6deba6095a342ede59d1afa8cb)

scene/gui/tree.cpp

@@ -3587,7 +3587,7 @@ void Tree::scroll_to_item(TreeItem *p_item) {
 
 	const Rect2 r = get_item_rect(p_item);
 
-	if (r.position.y < v_scroll->get_value()) {
+	if (r.position.y <= v_scroll->get_value()) {
 		v_scroll->set_value(r.position.y);
 	} else if (r.position.y + r.size.y + 2 * cache.vseparation > v_scroll->get_value() + get_size().y) {
 		v_scroll->set_value(r.position.y + r.size.y + 2 * cache.vseparation - get_size().y);