Remove tinc.service, it is not necessary.

Thanks to Alexander Ried for pointing out that if you have
tinc@.service template, systemd will provide a default slice containing
all instances of that template. So "systemctl start tinc" will still do
what we want it to do.

systemd/Makefile.am

@@ -1,4 +1,4 @@
 if WITH_SYSTEMD
 systemddir = @systemd_path@
-dist_systemd_DATA = tinc.service tinc@.service
+dist_systemd_DATA = tinc@.service
 endif

systemd/tinc.service

@@ -1,20 +0,0 @@
-# This is a mostly empty service, but allows commands like stop, start, reload
-# to propagate to all tinc@ service instances.
-
-[Unit]
-Description=Tinc VPN
-Documentation=info:tinc
-Documentation=man:tinc(8) man:tinc.conf(5)
-Documentation=http://tinc-vpn.org/docs/
-After=network.target
-Wants=network.target
-
-[Service]
-Type=oneshot
-RemainAfterExit=yes
-ExecStart=/bin/true
-ExecReload=/bin/true
-WorkingDirectory=/etc/tinc
-
-[Install]
-WantedBy=multi-user.target