Fix subtle bug in return value.

In python:

>>> res = False
>>> print (True if res == 0 else False)
True

To sum up True and False in a sentence: they're alternative ways
to spell the integer values 1 and 0, with the single difference
that str() and repr() return the strings
'True' and 'False' instead of '1' and '0'.

There are a lot of other places in the notifier where this is wrong
however it's not clear what might be depending on the wrong
behavior.