Fix template missing DATABASE_ENGINE

openshift/django-source-postgresql.json

@@ -305,6 +305,11 @@
       "description": "Database service name",
       "value": "postgresql"
     },
+    {
+      "name": "DATABASE_ENGINE",
+      "description": "Database engine: postgresql, mysql or sqlite (default)",
+      "value": "postgresql"
+    },
     {
       "name": "DATABASE_NAME",
       "description": "Database name",