Nonmatching transport in server reply” when cv2.VideoCapture rtsp onvif camera, how to fix?

edit

I'm on windows 10 using python 3.6.4, installed opencv (3.4) through pip. Here's the code I'm using:

import numpy as np
import cv2
cap = cv2.VideoCapture("rtsp://192.168.0.100:554/onvif1")
while(True):
    ret, frame = cap.read()
    print(frame)
    cv2.imshow('frame',frame)
    if cv2.waitKey(1) & 0xFF == ord('q'):
        break
cap.release()
cv2.destroyAllWindows()

[rtsp @ 0000016f6d5995a0] Nonmatching transport in server reply warning: Error opening file (/build/opencv/modules/videoio/src/cap_ffmpeg_impl.hpp:834) warning: rtsp://192.168.0.100:554/onvif1 (/build/opencv/modules/videoio/src/cap_ffmpeg_impl.hpp:835)

But when I'm using ffmpeg code:

ffplay rtsp://192.168.0.100:554/onvif1 --> Capture oke
ffplay -rtsp_transport udp rtsp://192.168.0.100:554/onvif1 --> Capture oke
ffplay -rtsp_transport tcp rtsp://192.168.0.100:554/onvif1 --> Nonmatching transport in server reply

I tried the following steps but don't work:

1 - change cap_ffmpeg_impl.hpp:
replace the line (798->801)
    +#else
        av_dict_set(&dict, "rtsp_transport", "tcp", 0);
    +#endif
         int err = avformat_open_input(&ic, _filename, NULL, &dict);
    with:
        int err = avformat_open_input(&ic, _filename, NULL, NULL);
2 - recompile opencv (http://www.learnopencv.com/install-opencv3-on-windows/).

Can you help me, please?