Revert "backport to stretch"

This reverts commit 1020ac96.

debian/control

@@ -3,8 +3,8 @@ Section: mail
 Priority: optional
 Maintainer: Mailman for Debian <pkg-mailman-hackers@lists.alioth.debian.org>
 Uploaders: Thijs Kinkhorst <thijs@debian.org>,
-Build-Depends: debhelper (>= 10), autoconf, python-dev,
- gettext, python-dnspython, dh-python, dh-systemd
+Build-Depends: debhelper (>= 11), autoconf, python-dev,
+ gettext, python-dnspython, dh-python
 Standards-Version: 4.1.4
 Homepage: http://www.list.org/
 Vcs-Git: https://salsa.debian.org/mailman-team/mailman2.git

debian/rules

@@ -121,8 +121,7 @@ binary-arch:	build
 		do dh_link usr/lib/$(package)/bin/$$bin usr/sbin/$$bin; done
 	mv debian/mailman/usr/sbin/arch debian/mailman/usr/sbin/mmarch
 	dh_installman
-	dh_systemd_enable
-	dh_systemd_start
+	dh_installsystemd
 	dh_installdebconf
 	dh_installexamples templates/* debian/mm_cfg.py \
 		debian/mailman/usr/lib/$(package)/Mailman/Defaults.py