Revert "Updated _slots_to_bin()"

This reverts commit eb3dbc0.

Author: Ayuto

addons/source-python/packages/source-python/menus/radio.py

@@ -91,14 +91,15 @@ def _slots_to_bin(slots):
         :param iterable slots: Slots that should be enabled.
         :raise ValueError: Raised if a slot is out of range.
         """
-        result = 0
+        # Keys are enabled in that order: 0987654321
+        buffer = list('0000000000')
         for slot in slots:
             if 0 <= slot <= 9:
-                result |= 1 << slot
+                buffer[~(slot - 1)] = '1'
             else:
                 raise ValueError('Slot out of range: {}'.format(slot))
 
-        return result
+        return int(''.join(buffer), 2)
 
     def _select(self, player_index, choice_index):
         """See :meth:`menus.base._BaseMenu._select`."""