patch: fix `ceph dashboard` subcommand becoming unavailable on crash

patch: fix `ceph dashboard` subcommand becoming unavailable on crash

Adapt the patch that originally disabled certain TLS checks during the
dashboard's startup and fixes the `ceph dashboard` subcommand becoming
unavailable if the dashboard crashes during that time.

This is achieved by re-implementing certain checks and also re-raising
any other unforeseen exceptions that occur in regards to TLS as one
of Ceph's internal exception types, which are then handled by the
dashboard itself. This is akin to how these cases were handled
originally.

Also fixes a typo in the `ceph dashboard create-self-signed-cert`
command output.

Signed-off-by: Max Carrara <m.carrara@proxmox.com>