Update refresh_products_tags.js
Update refresh_products_tags.js

Corrections after stephane reviews
- dbname is specified directly in command line
- indexes are build in background
openfoodfacts/openfoodfacts-server,openfoodfacts/openfoodfacts-server,openfoodfacts/openfoodfacts-server,openfoodfacts/openfoodfacts-server,openfoodfacts/openfoodfacts-server