fixed object.__new__ error message for >=2.7.4

Looks like this error message changed in 2.7.4... I don't know how you want to handle this kind of thing in general but this would make it a lot more convenient for me to run all the tests.
Unfortunately, none at the moment :/  I don't know enough about how those are used to know if they're consistent; a quick grep through the Modules directory seems to show that they're typically used in #ifdefs to check between major version changes.  It'd be nice if they were unified, though their use in #ifdefs means we'd have to give up on having them being set dynamically.

For now let's just leave the patchlevel.h ones at 2.7.7 and do the changes here -- we can punt on deciding one way or another until we have a better understanding of the choices.