Install systemd services with autotools

Change-Id: I3a87d5ad4cb43efdcfc25828144f825f4d3b1594
diff --git a/debian/osmo-msc.install b/debian/osmo-msc.install
index 6b84b8f..1e7f22f 100644
--- a/debian/osmo-msc.install
+++ b/debian/osmo-msc.install
@@ -1,3 +1,4 @@
+lib/systemd/system/osmo-msc.service
 usr/bin/osmo-msc
 usr/share/doc/osmo-msc/examples/osmo-msc/osmo-msc.cfg usr/share/doc/osmo-msc/examples
 usr/share/doc/osmo-msc/examples/osmo-msc/osmo-msc_custom-sccp.cfg usr/share/doc/osmo-msc/examples