Otherwise migration during which we didn't send client_migrate_info QMP
command will get stuck waiting for SPICE migration to finish if libvirtd
sent the QMP command in a previous migration attempt.

Broken by bd7c8a69.

https://bugzilla.redhat.com/show_bug.cgi?id=1151723Signed-off-by: NJiri Denemark <jdenemar@redhat.com>