fix wrong regex

Author: h-mayorquin

neo/rawio/blackrockrawio.py

@@ -1476,7 +1476,7 @@ def _match_nsx_and_nev_segment_ids(self, nsx_nb):
             # replacing event ids by matched event ids in place
             for k, (data, ev_ids) in self.nev_data.items():
                 if len(ev_ids):
-                    ev_ids[:] = np.vectorize(new_nev_segment_id_mapping._getitem__)(ev_ids)
+                    ev_ids[:] = np.vectorize(new_nev_segment_id_mapping.__getitem__)(ev_ids)
 
     def _read_nev_data_variant_a(self):
         """