Account metadata has incorrect container metadata

[csc-felipe]

Description

Account listing and header metadata should contain the list of containers with number of objects and total size. However, it doesn't reflect actual totals.

Command: curl -i http://localhost:5000/v3?format=json -X GET -H "X-Auth-Token: $token"

API docs

Definition of done

Account listing returns expected stats, with expected values for the number of objects and total size.