please tag libvirt-0.7.1-8.fc12 into dist-f12

libvirt-0.7.1-8.fc12 contains two fixes:

• Disable sound backend, even when selinux is disabled (#524499)
• Re-label qcow2 backing files (#497131)

The former is a more comprehensive patch from upstream replacing
an existing non-upstream patch. The old patch doesn't work with
selinux disabled because of the VirtPrivileges feature.

The latter is an issue with sVirt discovered during F-11, but has
gained importance because we're advertising better qcow2 support
as an F-12 feature. Fixes for this issue are pulled from latest
upstream.

I've just done some testing of the build and it seems fine