[libvirt] [PATCH] Increase initial qemu monitor read timeout

See https://bugzilla.redhat.com/show_bug.cgi?id=453491 We've been getting bug reports like the above against virt-manager for a while now: installing new VMs consistently throws an error 'Timed out while reading monitor startup output'. The user can then just retry the install and it will go off without a hitch. I only just realized that the common thread between the reports is physical install media: apparently the qemu monitor isn't too responsive while it's waiting for a cold cd drive to spin up. The attached patch jacks up the timeout from 3 seconds to 10 seconds when doing the initial monitor read. I verified that this fixes the issue. Thanks, Cole