Don't override default value for eventlet.wsgi.server logging

We want eventlet.wsgi.server to use the same log level as everything
else (by default). For example if INFO logging is enabled eventlet.wsgi.server will
log all API requests. So if INFO logging is enabled in the API server we
want eventlet.wsgi.server to use the same log level.

This only changes a default value, and can be set by the user.

Change-Id: I42124793bbf542d69f6493bb3a9611e443775c2a
Merge "Don't override default value for eventlet.wsgi.server logging"