Using both opencv-python and opencv-python-headless

[s39674]

Hi! I already have the first package of opencv-python and using it for my project. But when i download EasyOCR it also download opencv-python-headless which cause conflict with the first package:

cv2.imshow('Original Image', img)
cv2.error: OpenCV(4.5.4) /tmp/pip-req-build-9vck9bv0/opencv/modules/highgui/src/window.cpp:1274: error: (-2:Unspecified error)
The function is not implemented. Rebuild the library with Windows, GTK+ 2.x or Cocoa support.
If you are on Ubuntu or Debian, install libgtk2.0-dev and pkg-config, then re-run cmake or configure script in function 'cvShowImage'

#630 did work for me, so i propose to check it in setup.py if the user has installed opencv-python<=4.5.4.60

Thanks!