Keystone now provides "member" by default.
It should not be a problem for upgrades when the configuration
is the default one, because Keystone is case-preserving and
Member and member are the considered the same:
https://docs.openstack.org/keystone/latest/admin/identity-case-insensitive.html
Change-Id: I3bd72631d57546dcf8b887833539fe3ccaac4e47
Luigi Toscano