Update admin-guide.md
Update admin-guide.md

Fix typo
gravitational/teleport,yacloud-io/teleport,yacloud-io/teleport,gravitational/teleport,yacloud-io/teleport,gravitational/teleport,gravitational/teleport,yacloud-io/teleport,yacloud-io/teleport,gravitational/teleport,yacloud-io/teleport,yacloud-io/teleport,gravitational/teleport