[BUG] Fix bug in {inc,set}_subtensor in advanced1 case

Reported by Stanislas Lauly

wrong results?
I mean that test_adv1_inc_sub_notlastdim_1dval and test_adv1_inc_sub_notlastdim_2dval where the same execpt for that line. The Theano function is build exactly the same way in both cases.