qemu: Properly reset spiceMigration flag
qemu: Properly reset spiceMigration flag

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=1151723

Signed-off-by: Jiri Denemark <62bdf77dc47919a4d59a91822129d14633cfca81@redhat.com>

fabianfreyer/libvirt,jfehlig/libvirt,eskultety/libvirt,zippy2/libvirt,eskultety/libvirt,taget/libvirt,crobinso/libvirt,libvirt/libvirt,nertpinx/libvirt,VenkatDatta/libvirt,andreabolognani/libvirt,jardasgit/libvirt,libvirt/libvirt,libvirt/libvirt,fabianfreyer/libvirt,andreabolognani/libvirt,fabianfreyer/libvirt,taget/libvirt,andreabolognani/libvirt,VenkatDatta/libvirt,libvirt/libvirt,datto/libvirt,jardasgit/libvirt,zippy2/libvirt,fabianfreyer/libvirt,jfehlig/libvirt,nertpinx/libvirt,jardasgit/libvirt,nertpinx/libvirt,crobinso/libvirt,nertpinx/libvirt,zippy2/libvirt,olafhering/libvirt,crobinso/libvirt,zippy2/libvirt,taget/libvirt,jfehlig/libvirt,jfehlig/libvirt,fabianfreyer/libvirt,crobinso/libvirt,jardasgit/libvirt,VenkatDatta/libvirt,olafhering/libvirt,olafhering/libvirt,VenkatDatta/libvirt,olafhering/libvirt,eskultety/libvirt,andreabolognani/libvirt,VenkatDatta/libvirt,datto/libvirt,datto/libvirt,eskultety/libvirt,taget/libvirt,datto/libvirt,jardasgit/libvirt,nertpinx/libvirt,datto/libvirt,eskultety/libvirt,andreabolognani/libvirt,taget/libvirt