conf/qemu: s/VIR_PCI_CONNECT_HOTPLUGGABLE/VIR_PCI_CONNECT_AUTOASSIGN/g

conf/qemu: s/VIR_PCI_CONNECT_HOTPLUGGABLE/VIR_PCI_CONNECT_AUTOASSIGN/g

When the HOTPLUGGABLE flag was originally added, it was set for all
the PCI controllers that accepted hotplugged devices, and requested
for all devices that were auto-assigned to a controller. While we're
still autoassigning to the same list of controllers, those controllers
may or may not support hotplug, so let's use the flag that fits what
we're actually doing.

Signed-off-by: Laine Stump <laine@redhat.com>
Reviewed-by: Michal Privoznik <mprivozn@redhat.com>