[TileSet] Fix crash when deleting dragged polygon point

editor/plugins/tiles/tile_data_editors.cpp

@@ -641,6 +641,7 @@ void GenericTilePolygonEditor::_base_control_gui_input(Ref<InputEvent> p_event)
 						undo_redo->add_undo_method(base_control, "queue_redraw");
 						undo_redo->commit_action(false);
 						emit_signal(SNAME("polygons_changed"));
+						drag_type = DRAG_TYPE_NONE;
 					} else {
 						drag_type = DRAG_TYPE_PAN;
 						drag_last_pos = mb->get_position();