Configure ssl_listener in stomp only for ssl

W/o this patch puppet will always configure
ssl_listener for stomp and rabbitmq service will
fail to start, if ssl => false.

The solution is to ignore ssl_stomp_port in
config_stomp stanza then ssl was not enabled
and issue a puppet warn about that as well.

Closes-bug: #MODULES-1414

Signed-off-by: Bogdan Dobrelya <bdobrelia@mirantis.com>