Remove double tcp_listen_options entries for rabbit

Remove double tcp_listen_options entries for rabbit

After a brand new deployment we have the following in rabbitmq.config:
...
  {rabbit, [
    {tcp_listen_options,
         [binary,
         {packet,        raw},
         {reuseaddr,     true},
         {backlog,       128},
         {nodelay,       true},
         {exit_on_close, false}]
    },
    {tcp_listen_options, [binary, {packet, raw}, {reuseaddr, true},
{backlog, 128}, {nodelay, true}, {exit_on_close, false}, {keepalive,
true}]},
...

Let's remove these duplicate entries and make sure that we use the
parameters for the puppet module to set the following values
explicitely (it's the only parameter where we do not use the default
setting from the puppet module):
keepalive = true -> rabbitmq::tcp_keepalive: true

All the other options that we set are the default in the puppet module:
{packet, raw}
{reuseaddr, true}
{backlog, 128}{nodelay, true}
{exit_on_close, false}

Depends-On: I608477d5714a5081b3b4ab3b9fc2932bdd598301
Change-Id: I35921652bd84d1d6be0727051294983d4a0dde10