Previously, onionAddresses definitions in onionServices were of the form
onionAddresses.access.<service> = [<service>];
This caused failures for configurations where a service user name was
overridden or for bitcoind whose default user is 'bitcoin' instead of 'bitcoind'.
Now set the equivalent of:
onionAddresses.access.<actualServiceUser> = [<service>];
Implement this via a new option `onionAddresses.services` to make things more
readable and to work around an infinite recursion error in onionServices.