compute: Better help text for 'openstack server set --state'
compute: Better help text for 'openstack server set --state'

Manually changing the server state is a potentially dangerous operation
that should only be done under limited circumstances. It's also an
admin-only operation by default. Highlight both points.

Change-Id: Ifd8aec94937764202131ba8caf6b507caa76d7e9
Signed-off-by: Stephen Finucane <492121341a95b3c3aab646bed44634f739dd019b@redhat.com>
Story: 2008549
Task: 41672

openstack/python-openstackclient,openstack/python-openstackclient