Install systemd services with autotools

Change-Id: Id81ae8e2d8a2c9456ac0dac2c30c0d24dab3b694
diff --git a/debian/osmo-hlr.install b/debian/osmo-hlr.install
index 7991522..5a7c37b 100644
--- a/debian/osmo-hlr.install
+++ b/debian/osmo-hlr.install
@@ -1,3 +1,4 @@
+/lib/systemd/system/osmo-hlr.service
 /usr/bin/osmo-hlr
 /usr/bin/osmo-hlr-db-tool
 /usr/share/doc/osmo-hlr/sql/hlr.sql