However, not sure if the check is neded. I mean:

* If CB runs with `-multitenant url` then you ignore the header and take into account the new token in the URL to set the proper tenant.
* If CB runs with `-multitenant header` then you will use the usual URLs (without extra token) and get the tenant from the header (if the header is missing, you assume default tenant, i.e. pass "" as tenant to the mongoBackend).