Typo fix.

Lib/decimal.py

@@ -731,7 +731,7 @@ class Decimal(object):
         """x.__hash__() <==> hash(x)"""
         # Decimal integers must hash the same as the ints
         # Non-integer decimals are normalized and hashed as strings
-        # Normalization assures that hast(100E-1) == hash(10)
+        # Normalization assures that hash(100E-1) == hash(10)
         if self._is_special:
             if self._isnan():
                 raise TypeError('Cannot hash a NaN value.')