Resolve "gunicorn.socket should allow to shutdown service without automatic reload on accesing IPv4 port"

Closes #353 (closed)

The service does not restart automatically.

Before removing socket I've tried following addition to the service without success:

ExecStopPost=-systemctl stop smasch.socket

ExecStopPost=systemctl stop smasch.socket

ExecStopPost=systemctl --user stop smasch.socket

The main problem was that stop was run with smasch user privileges and this user could not exec systemctl.