System information (version)

• OpenCV => 4.3.0-dev
• Operating System / Platform => Windows7 32 Bit
• Compiler => mingw64(8.1)

Detailed description

while checking out a ultra small(500k !) yolov3 model from here i got a :

cv2.error: OpenCV(4.3.0-dev) C:\p\opencv\modules\dnn\src\darknet\darknet_io.cpp:831: error: (-212:Parsing error) Unsupported activation: relu in function 'ReadDarknetFromCfgStream'

it has a couple of activation=relu lines, e.g. here but in darknet_io.cpp there is only a leaky activation:

calling this:

so, this is indeed the "leaky" variant (used in all other yolo models), and real "relu" would have a slope of 0.0, right ?

Steps to reproduce

net = cv.dnn.readNet('yoloface-500k.cfg', 'yoloface-500k.weights')

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