Use the correct parameters for role assignements list

Since [1], keystone requires, for the role assignements index API call,
only the parameters defined in ``role_assignments_index_request_query``.

[1]https://review.opendev.org/c/openstack/keystone/+/940344

Change-Id: I67e7f81b460e9517fc77d96bc4f35ef9300dbf74
1 file changed