Revert "Change the libvirtd log level to DEBUG"

Suggested by Daniel Berrange in this thread:
http://lists.openstack.org/pipermail/openstack-dev/2014-January/024407.html

This reverts commit 3bd85c9d6e257fc952cb3c6d0c09e199685bd5ed.

Change-Id: I370ba61cf8a00b51684cd504fed4ba4078d868be
Merge "Revert "Change the libvirtd log level to DEBUG""
Merge branch 'master' of github.com:openstack-dev/devstack