These are no longer necessary with the removal of cells v1. A check for
cells v1 in 'nova-manage cell_v2 simple_cell_setup' is also removed,
meaning this can no longer return the '2' exit code.
Part of blueprint remove-cells-v1
Change-Id: I8c2bfb31224300bc639d5089c4dfb62143d04b7f
Signed-off-by: Stephen Finucane <sfinucan@redhat.com>