[Bf-python] typo in epydocs

[Campbell Barton]

Epydoc object.Layers example is incorrect, confusing.


      Layers

The object layers (also check the newer attribute |layers|). This value 
is a bitmask with at least one position set for the 20 possible layers 
starting from the low order bit. The easiest way to deal with these 
values in in hexadecimal notation. Example:

 ob.Layer = 0x04 # sets layer 3 ( bit pattern 0100 )