--tls-destination would be just ignored unless --tls is not specified,
which is correct, but let's provide a bit of a guidance is a user
forgets to add --tls.
This is just a virsh-only check targeted to end users as we don't
currently have such checks at the API level for migration parameters
that depend on flags.
https://bugzilla.redhat.com/show_bug.cgi?id=1784345
Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
Acked-by: Peter Krempa <pkrempa@redhat.com>