BUG: fix reference counting error in wrapping_method_resolve_descriptors

[ngoldbaum]

It looks like this copy/paste error has been here for two years!

This was found in the nogil python build, which may find other reference counting bugs that a more forgiving GIL implementation wasn't bothered by.

[ngoldbaum]

The nogil build stores the reference counts in a different spot in the PyObject struct and the reference counting logic is a bit more complicated, so it touches more places in memory than the old logic did. I think it was just dumb luck that we didn't seg fault with older python versions but now that python's reference counting internals changed we're finally getting in trouble for this bug.

[charris]

Thanks Nathan.