Minor fix ensuring good values in output
Minor fix ensuring good values in output

invert_flags in collapse mode got unexpected values (not boolean)
for nonlinear transform

fprados/nipype,arokem/nipype,gerddie/nipype,pearsonlab/nipype,JohnGriffiths/nipype,wanderine/nipype,grlee77/nipype,grlee77/nipype,blakedewey/nipype,glatard/nipype,pearsonlab/nipype,carolFrohlich/nipype,sgiavasis/nipype,dmordom/nipype,mick-d/nipype,mick-d/nipype,arokem/nipype,dgellis90/nipype,gerddie/nipype,fprados/nipype,arokem/nipype,wanderine/nipype,grlee77/nipype,glatard/nipype,glatard/nipype,gerddie/nipype,arokem/nipype,carolFrohlich/nipype,FCP-INDI/nipype,mick-d/nipype,sgiavasis/nipype,iglpdc/nipype,rameshvs/nipype,dgellis90/nipype,sgiavasis/nipype,carolFrohlich/nipype,FCP-INDI/nipype,Leoniela/nipype,fprados/nipype,Leoniela/nipype,dmordom/nipype,grlee77/nipype,FCP-INDI/nipype,rameshvs/nipype,wanderine/nipype,blakedewey/nipype,FCP-INDI/nipype,wanderine/nipype,dgellis90/nipype,iglpdc/nipype,gerddie/nipype,JohnGriffiths/nipype,dgellis90/nipype,mick-d/nipype,rameshvs/nipype,blakedewey/nipype,carolFrohlich/nipype,dmordom/nipype,iglpdc/nipype,JohnGriffiths/nipype,pearsonlab/nipype,JohnGriffiths/nipype,blakedewey/nipype,iglpdc/nipype,rameshvs/nipype,sgiavasis/nipype,Leoniela/nipype,pearsonlab/nipype,glatard/nipype