System information (version)

• OpenCV => 4.4.0.46
• Operating System / Platform => Linux 64 Bit - Python - Docker Container datascience-notebook

Detailed description

Loading ONNX model throws an exception in onnx_graph_simplifier.cpp

Steps to reproduce

import cv2
net=cv2.dnn.readNetFromONNX('./onnx.model')

Model available to reproduce the issue at: Google Drive onnx.model

error: OpenCV(4.4.0) /tmp/pip-req-build-cg56sov1/opencv/modules/dnn/src/onnx/onnx_graph_simplifier.cpp:526: 
          error: (-210:Unsupported format or combination of formats) Unsupported data type: INT32 in function
          'getMatFromTensor'

Issue submission checklist

• I report the issue, it's not a question
• I checked the problem with documentation, FAQ, open issues,
  answers.opencv.org, Stack Overflow, etc and have not found solution
• I updated to latest OpenCV version and the issue is still there
• There is reproducer code and related data files: videos, images, onnx, etc - model can be loaded with netron