remove incorrect decrefs
remove incorrect decrefs

PyList_SetItem will call Py_XDECREF for us.
https://github.com/python/cpython/blob/bb3e0c240bc60fe08d332ff5955d54197f79751c/Objects/listobject.c#L248-L257

eddelbuettel/annoy,eddelbuettel/annoy,eddelbuettel/annoy,eddelbuettel/annoy,spotify/annoy,spotify/annoy,spotify/annoy,spotify/annoy