Revert "[strided_slice] handle negative strided_begin before shrink_axis_mask_"

This reverts commit 4fa67f8.

Author: snoopyisadog

src/caffe/layers/strided_slice_layer.cpp

@@ -33,12 +33,6 @@ void StridedSliceLayer<Dtype>::LayerSetUp(const vector<Blob<Dtype> *> &bottom,
     strides_.assign(strided_begin_.size(), 1);
   }
 
-  for (int i = 0; i < strided_begin_.size(); ++i) {
-    if (strided_begin_[i] < 0) {
-      strided_begin_[i] = std::max(strided_begin_[i] + bottom[0]->shape(i), 0);
-    }
-  }
-
   // add onnx operator Slice parameter: axes
   axes_.clear();
   std::copy(strided_slice_param.axes().begin(),