fix array input for precession variables in conversion.py

bilby/gw/conversion.py

@@ -156,7 +156,10 @@ def transform_precessing_spins(*args):
     :code:`bilby.gw.conversion.bilby_to_lalsimulation_spins`.
     This will be removed from the public API in a future release.
     """
-    return lalsim_SimInspiralTransformPrecessingNewInitialConditions(*args)
+    iota, spin_1x, spin_1y, spin_1z, spin_2x, spin_2y, spin_2z = \
+        lalsim_SimInspiralTransformPrecessingNewInitialConditions(*args)
+
+    return iota, spin_1x, spin_1y, spin_1z, spin_2x, spin_2y, spin_2z
 
 
 def convert_to_lal_binary_black_hole_parameters(parameters):