Use dh-systemd to install the service file, but don't enable it automatically

debian/control

@@ -4,6 +4,7 @@ Homepage: http://poptop.sourceforge.net/dox/
 Standards-Version: 3.9.6
 Build-Depends: debhelper (>= 9),
     automake,
+    dh-systemd,
     libwrap0-dev,
     ppp-dev (>= 2.4.6-2~),
 Priority: optional

debian/pptpd.install

@@ -10,4 +10,3 @@ debian/pptpd-options            etc/ppp/
 
 usr/lib/pptpd/pptpd-logwtmp.so
 
-debian/pptpd.service            lib/systemd/system/

debian/rules

@@ -1,7 +1,7 @@
 #!/usr/bin/make -f
 
 %:
-	dh $@
+	dh $@ --with systemd
 
 override_dh_auto_configure:
 	autoreconf --force --install
@@ -19,3 +19,6 @@ override_dh_installdocs:
 
 override_dh_installinit:
 	dh_installinit -- start 20 2 3 4 5 . stop 20 1 .
+
+override_dh_systemd_enable:
+	dh_systemd_enable --no-enable