Loading ZConfig will initialize storage and generally might do things
that will cause messages to be emitted.
One actual problem is with neo storage, which configure root logger
when it's not already configured [1], this was causing all logged
messages to be logged in the console when using neo storage.

1: https://lab.nexedi.com/nexedi/neoppod/blob/fd87e153/neo/lib/logger.py#L63-64