add history to equirect import

src/node_panel_layer.cpp

@@ -507,7 +507,7 @@ Action* ActionLayerMerge::get_redo()
     a->m_layer_node = m_layer_node;
     a->m_panel = m_panel;
     a->m_snap = m_snap;
-    a->m_direction = m_direction == Direction::Undo ? Direction::Redo : Direction::Undo;
+    a->m_direction = reverse_direction();
     return a;
 }