BUG: stats._unuran: fix remaining attribute lookup errors
BUG: stats._unuran: fix remaining attribute lookup errors

zerothi/scipy,mdhaber/scipy,vigna/scipy,perimosocordiae/scipy,scipy/scipy,vigna/scipy,scipy/scipy,zerothi/scipy,WarrenWeckesser/scipy,WarrenWeckesser/scipy,scipy/scipy,zerothi/scipy,andyfaff/scipy,vigna/scipy,mdhaber/scipy,scipy/scipy,anntzer/scipy,Stefan-Endres/scipy,endolith/scipy,endolith/scipy,anntzer/scipy,endolith/scipy,andyfaff/scipy,rgommers/scipy,perimosocordiae/scipy,ilayn/scipy,WarrenWeckesser/scipy,Stefan-Endres/scipy,ilayn/scipy,perimosocordiae/scipy,anntzer/scipy,endolith/scipy,mdhaber/scipy,WarrenWeckesser/scipy,WarrenWeckesser/scipy,Stefan-Endres/scipy,zerothi/scipy,andyfaff/scipy,rgommers/scipy,scipy/scipy,endolith/scipy,Stefan-Endres/scipy,ilayn/scipy,anntzer/scipy,ilayn/scipy,vigna/scipy,andyfaff/scipy,vigna/scipy,endolith/scipy,Stefan-Endres/scipy,scipy/scipy,rgommers/scipy,anntzer/scipy,zerothi/scipy,WarrenWeckesser/scipy,mdhaber/scipy,perimosocordiae/scipy,anntzer/scipy,perimosocordiae/scipy,andyfaff/scipy,Stefan-Endres/scipy,mdhaber/scipy,ilayn/scipy,ilayn/scipy,zerothi/scipy,mdhaber/scipy,perimosocordiae/scipy,rgommers/scipy,rgommers/scipy,andyfaff/scipy