Ephemerids doesn't function

[ziriuz84]

Describe the bug
When I search for ephemerids of an object it crashes completely

To Reproduce

1. Go to Object Ephemerids
2. Insert a known object like 12P

Expected behavior
It gives ephemerids of object

Traceback (most recent call last):
  File "/home/sirio/Projects/asteroidpy/env/bin/asteroidpy", line 33, in <module>
    sys.exit(load_entry_point('AsteroidPy', 'console_scripts', 'asteroidpy')())
             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/sirio/Projects/asteroidpy/asteroidpy/__init__.py", line 24, in main
    interface.interface(config)
  File "/home/sirio/Projects/asteroidpy/asteroidpy/interface.py", line 511, in interface
    main_menu(config)
  File "/home/sirio/Projects/asteroidpy/asteroidpy/interface.py", line 496, in main_menu
    scheduling_menu(config)
  File "/home/sirio/Projects/asteroidpy/asteroidpy/interface.py", line 465, in scheduling_menu
    object_ephemeris_menu(config)
  File "/home/sirio/Projects/asteroidpy/asteroidpy/interface.py", line 564, in object_ephemeris_menu
    ephemeris = scheduling.object_ephemeris(config, object_name, step)
                ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/sirio/Projects/asteroidpy/asteroidpy/scheduling.py", line 534, in object_ephemeris
    str(object_name).upper(), location=location, step=step, number=30
                                                      ^^^^
UnboundLocalError: cannot access local variable 'step' where it is not associated with a value