Use MaaS node key when on_maas

Change-Id: Ie5708aac996647ee532d33a82ec5e9af468645a8
diff --git a/roles/onos-vm-install/files/onos-docker-compose.yml b/roles/onos-vm-install/files/onos-docker-compose.yml
index 09255fa..c57afcb 100644
--- a/roles/onos-vm-install/files/onos-docker-compose.yml
+++ b/roles/onos-vm-install/files/onos-docker-compose.yml
@@ -15,5 +15,4 @@
       - "9876"
       network_mode: host
       volumes:
-      - ./id_rsa:/root/node_key:ro
-
+      - ./node_key:/root/node_key:ro