add working gstreamer udp sink example to README

I couldn't get the example in the VideoReceiver README.md to work properly on Windows 10.  I found a command that worked for me and so that the next user doesn't lose 2 hours trying to solve the same problem, I'm adding it here.

src/VideoReceiver/README.md

@@ -41,6 +41,10 @@ On the receiving end, if you want to test it from the command line, you can use
 ```
 gst-launch-1.0 udpsrc port=5600 caps='application/x-rtp, media=(string)video, clock-rate=(int)90000, encoding-name=(string)H264' ! rtpjitterbuffer ! rtph264depay ! h264parse ! avdec_h264 ! autovideosink fps-update-interval=1000 sync=false
 ```
+Or this one:
+```
+gst-launch-1.0 udpsrc port=5600 ! application/x-rtp ! rtpjitterbuffer ! rtph264depay ! avdec_h264 ! videoconvert ! autovideosink
+```
 
 ### Additional Protocols