Rucio URL needs to be configured in two places

When I set up my own ESAP that needs to talk to its own Rucio instance, I have to configure the URL both in the envrionment through the RUCIO_HOST and RUCIO_AUTH_HOST as well as in the esap/esap/esap_config.yaml file which contains a url and a user_url. This is not really documented and may lead to some weird errors because the URL used to list the scopes is taken from the environment while the URL that is used to find the files within a scope is taken from the latter.

I am looking into this so I may propose a fix today.