update import

theano/tensor/nnet/opt.py

@@ -13,7 +13,7 @@ from theano.tensor.nnet.blocksparse import (
     SparseBlockOuter,
     sparse_block_gemv_inplace,
     sparse_block_outer_inplace)
-from theano.tensor.nnet.abstract_conv2d import (AbstractConv2d,
+from theano.tensor.nnet.abstract_conv import (AbstractConv2d,
                                               AbstractConv2d_gradWeights,
                                               AbstractConv2d_gradInputs)
 from theano.tensor.opt import register_specialize_device