Fix handling of optional params in blockCopy()
Fix handling of optional params in blockCopy()

Commit 2b4bd07e0a22 (Add check for params, nparams being a dictionary)
changed the way the optional params argument is treated. If
libvirt.virDomain.blockCopy() is called without specifying params,
params is None, and the call will fail with:

    TypeError: block params must be a dictionary

This is wrong as params is defined as kwarg, breaking existing libvirt
users like oVirt. Add a check for Py_None, so we accept either a dict or
None and fail with TypeError with anything else.

Resolves: https://bugzilla.redhat.com/1687114

Signed-off-by: Nir Soffer <60258c486a9660a474d408e6013543d2add80a76@redhat.com>

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