Make sure nova-compute is not configured with database access

Apparently we're inheriting some database config from the main file,
which should not be set for nova-compute. If we're properly in superconductor
mode where we have a dedicated config for compute, remove those lines
if present.

Closes-Bug: #1797413

Change-Id: I4820abe57a023050dd8d067c77e26028801ff288
diff --git a/lib/nova b/lib/nova
index 5e157c5..8b49116 100644
--- a/lib/nova
+++ b/lib/nova
@@ -922,6 +922,9 @@
         # RPC, we also disable track_instance_changes.
         iniset $NOVA_CPU_CONF filter_scheduler track_instance_changes False
         iniset_rpc_backend nova $NOVA_CPU_CONF DEFAULT "nova_cell${NOVA_CPU_CELL}"
+        # Make sure we nuke any database config
+        inidelete $NOVA_CPU_CONF database connection
+        inidelete $NOVA_CPU_CONF api_database connection
     fi
 
     # Console proxies were configured earlier in create_nova_conf. Now that the