fix error : AttributeError: spin1z

/home/vinaya.valsan/rapidPE/RapidPE_RIFT_Developments/RapidPE-RIFT_fork/mixed_coordinates/output/mixed_coord/mu1mu2_test2/logs/GridRefine-303091919-0.err

Traceback (most recent call last):
  File "/home/vinaya.valsan/virtualenvs/igwn-py38-rapidpe-rift/bin/rapidpe_compute_intrinsic_grid", line 7, in <module>
    exec(compile(f.read(), __file__, 'exec'))
  File "/home/vinaya.valsan/virtualenvs/igwn-py38-rapidpe-rift/src/rapidpe/bin/rapidpe_compute_intrinsic_grid", line 398, in <module>
    res_pts = numpy.array([tuple(getattr(t, a) for a in intr_prms) for t in results])
  File "/home/vinaya.valsan/virtualenvs/igwn-py38-rapidpe-rift/src/rapidpe/bin/rapidpe_compute_intrinsic_grid", line 398, in <listcomp>
    res_pts = numpy.array([tuple(getattr(t, a) for a in intr_prms) for t in results])
  File "/home/vinaya.valsan/virtualenvs/igwn-py38-rapidpe-rift/src/rapidpe/bin/rapidpe_compute_intrinsic_grid", line 398, in <genexpr>
    res_pts = numpy.array([tuple(getattr(t, a) for a in intr_prms) for t in results])
AttributeError: spin1z