[FIX] hw_drivers: Kill eftdvs w/o Six terminal

If no Six Payment terminal is configured, kill eftdvs if it is running.

When removing the configuration for a Six payment terminal, we just
removed the file with the configuration but we didn't stop eftdvs. The
terminal the nstayed connected to this Box even after removing the
configuration, blocking the connection to another terminal.

addons/hw_drivers/controllers/driver.py

@@ -474,6 +474,11 @@ if terminal_id:
     eftapi = ctypes.CDLL("eftapi.so")  # Library given by Six
     mpdm.daemon = True
     mpdm.start()
+else:
+    try:
+        subprocess.check_call(["pkill", "9", "eftdvs"])  # Check if MPD server is running
+    except subprocess.CalledProcessError:
+        pass
 
 m = Manager()
 m.daemon = True