This use-case was broken by commit
<fa6bdf6afa878b8d7c5ed71664ee72be8967cdc5>.
We allowed this configuration and it was working as expected therefore
we can consider it as regression. We should have never allowed such
configuration so now the best solution is in case of non-numa guest
silently ignore the 'nodeset' attribute if it's set to '0'.
That will be fixed by following patches.
Signed-off-by: Pavel Hrdina <phrdina@redhat.com>