Remove unused method setup_logging

Method setup_logging in glance/common/config.py wasn't used anywhere.
Similar function is in oslo, and some modules in Glance are using
function log.setup from oslo, like glance/cmd/manage.py#L123

Closes-Bug: #1248214

Change-Id: Icda26943f02df5e495179868aa8b1f4c4e151803
Merge "Remove unused method setup_logging"