Set config file to db sync and other manage operation

Currently, the db sync operation does not specify the config dir or
config file.
If there is a config file in the home path, it will use this one,
but not the right one devstack write.

Set config file to these operations.

Change-Id: Id1fbc3d85280c19596f5ebd301c46bcf018fa2f6
Closes-Bug: #1578098
diff --git a/lib/nova b/lib/nova
index 818ecc4..7f64016 100644
--- a/lib/nova
+++ b/lib/nova
@@ -702,18 +702,18 @@
         recreate_database nova
 
         # Migrate nova database
-        $NOVA_BIN_DIR/nova-manage db sync
+        $NOVA_BIN_DIR/nova-manage --config-file $NOVA_CONF db sync
 
         if is_service_enabled n-cell; then
             recreate_database $NOVA_CELLS_DB
         fi
 
         recreate_database $NOVA_API_DB
-        $NOVA_BIN_DIR/nova-manage api_db sync
+        $NOVA_BIN_DIR/nova-manage --config-file $NOVA_CONF api_db sync
 
         # Run online migrations on the new databases
         # Needed for flavor conversion
-        $NOVA_BIN_DIR/nova-manage db online_data_migrations
+        $NOVA_BIN_DIR/nova-manage --config-file $NOVA_CONF db online_data_migrations
     fi
 
     create_nova_cache_dir