fix Type error

MY bad..
```
Traceback (most recent call last):
  File "/home/jihoonl/research/ros/turtlebot/src/rocon_qt_gui/rocon_qt_library/src/rocon_qt_library/widgets/slam_widget.py", line 92, in save_map
    self._callback['save_map'](world=world_name, map_name=map_name)
  File "/home/jihoonl/research/ros/turtlebot/src/rocon_qt_gui/rocon_qt_library/src/rocon_qt_library/interfaces/slam_widget_interface.py", line 71, in save_map
    ac.save()
  File "/home/jihoonl/research/ros/turtlebot/src/world_canvas_libs/world_canvas_client_py/src/world_canvas_client/annotation_collection.py", line 400, in save
    len(self.annotations), len(self.annots_data), len(annotations), len(annots_data))
TypeError: str() takes at most 1 argument (5 given)
```