fixed server starting in venv, and not system-wide

[Kortho]

server.py was started with system-wide python env. source makes it run in venv

[mokaddem]

I'm not sure this is the correct way to do it.
IMHO, you should be in an virtualenv before starting start_all.sh

[Kortho]

sort of agree, but if so, it should be "python3 ${DIR}/server.py &"
And all the stuff with venv could just be removed. By doing it this way, the code works, and the user does not have to worry about it at all (make it easier to be more secure for the user)