the filter tries to use list_extensions API of novaclient,
however it was removed in Ussuri release
https://review.opendev.org/c/openstack/python-novaclient/+/686516
All the former extensions are long ago rolled into Nova "core" code,
so we may take the "extension" this filter depends on as given.
Change-Id: Idc03d997cfedfc2fcc967cca519997d157df115a
(cherry picked from commit 738f81feeb)
(cherry picked from commit d2dc171b02)