fixing output_spec is not callable
fixing output_spec is not callable

FCP-INDI/nipype,carolFrohlich/nipype,sgiavasis/nipype,mick-d/nipype,carolFrohlich/nipype,sgiavasis/nipype,mick-d/nipype,mick-d/nipype,sgiavasis/nipype,FCP-INDI/nipype,mick-d/nipype,sgiavasis/nipype,FCP-INDI/nipype,carolFrohlich/nipype,carolFrohlich/nipype,FCP-INDI/nipype