qemuDomainSetIOThreadParams: Accept VIR_DOMAIN_AFFECT_CONFIG flag
qemuDomainSetIOThreadParams: Accept VIR_DOMAIN_AFFECT_CONFIG flag

It was always possible to modify the inactive XML, because
VIR_DOMAIN_AFFECT_CURRENT (= 0) is accepted implicitly. But now
that the logic when changing both config and live XMLs is more
robust we can accept VIR_DOMAIN_AFFECT_CONFIG flag too.

Signed-off-by: Michal Privoznik <83d82aaba2eed257f4814b0c239c260c4caaadf0@redhat.com>
Reviewed-by: Ján Tomko <4cab11cfb98d3c937327354a78eb07dbb6ee2bc6@redhat.com>

olafhering/libvirt,libvirt/libvirt,crobinso/libvirt,jfehlig/libvirt,olafhering/libvirt,zippy2/libvirt,libvirt/libvirt,crobinso/libvirt,zippy2/libvirt,libvirt/libvirt,jfehlig/libvirt,crobinso/libvirt,zippy2/libvirt,olafhering/libvirt,libvirt/libvirt,zippy2/libvirt,jfehlig/libvirt,jfehlig/libvirt,crobinso/libvirt,olafhering/libvirt