Wait for connack before doing anything else.

[samlaf]

Many issues have been raised regarding video timeouts when using keyboard_and_video.py

I believe the issue comes from not calling wait_for_connection between connect and start_video

I never have issues with video_effect.py and wait_for_connection is the only explanation I could find. I haven't been having issues with keyboard_and_video ever since.

I find forcing the users to call wait_for_connection themselves to be very bug-prone (as we can see from this example), so I have opted to move it directly in connect. This should take care of these issues forever.