Add build/ to python module path for sanitytest.py
Add build/ to python module path for sanitytest.py

The generated libvirt.py modules will be in the build/
directory, so santitytest.py must use that directory.

Signed-off-by: Daniel P. Berrange <bb938cf255e055ff3507f2627d214e8e62118fcf@redhat.com>

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