Don't add working directory to Python's path

When the service is called via qrexec this results in the home directory
being in Pyhton's sys.path which means Python is looking for modules
there too.

Author: HW42

qubes.Gpg2.service

@@ -7,4 +7,4 @@ for d in /etc "${XDG_CONFIG_HOME:-$HOME/.config}"; do
     fi
 done
 
-/usr/bin/python3 -m splitgpg2
+/usr/bin/python3 -P -m splitgpg2