python: prefer unsigned flags
python: prefer unsigned flags

* python/libvirt-override.c (libvirt_virConnectOpenAuth)
(libvirt_virDomainSnapshotListNames)
(libvirt_virDomainRevertToSnapshot): Change flags type.

libvirt/libvirt-python,cardoe/libvirt-python,libvirt/libvirt-python,cardoe/libvirt-python,cardoe/libvirt-python,libvirt/libvirt-python