add systemd unit (#659919)

drop sysconfig file

transmission-daemon-systemd

@@ -0,0 +1,13 @@
+# To customize, copy this file to /etc/systemd/system and edit there
+
+[Unit]
+Description=Transmission BT Client headless
+After=syslog.target network.target
+
+[Service]
+User=transmission
+ExecStart=/usr/bin/transmission-daemon -f -T --blocklist -g /var/lib/transmission/.config/transmission
+StandardError=syslog
+
+[Install]
+WantedBy=multi-user.target