remove unnecessary --no-restart-after-upgrade

("Undo a previous --restart-after-upgrade (or the default of compat 10). If no other options are given, this will cause the service to be stopped in the prerm script and started again in the postinst script.")

debian/rules

@@ -9,7 +9,7 @@
 	dh $@ --with=config-package
 
 override_dh_installsystemd:
-	dh_installsystemd --no-start --no-restart-after-upgrade --no-stop-on-upgrade
+	dh_installsystemd --no-start --no-stop-on-upgrade
 
 override_dh_installchangelogs:
 	dh_installchangelogs changelog.upstream upstream