dlm: reject SCTP configuration if not enabled

Reject SCTP dlm configuration if the kernel was never build with SCTP.
Currently the only one known user space tool "dlm_controld" will drop an
error in the logs and getting stuck. This behaviour should be fixed to
deliver an error to the user or fallback to TCP.

Signed-off-by: Alexander Aring <aahringo@redhat.com>
Reviewed-by: Heming zhao <heming.zhao@suse.com>
Signed-off-by: David Teigland <teigland@redhat.com>