Use systemd restart

src/freedombone-addsipuser

     echo "SIP user $MY_USERNAME added"
 fi
 
-service sipwitch restart
+systemctl restart sipwitch
 
 exit 0

src/freedombone-rmsipuser

 
 remove_sip_user
 
-service sipwitch restart
+systemctl restart sipwitch
 
 echo "SIP user $MY_USERNAME removed"
 exit 0