Populating sentinel configuration to Consul nodes should check if a redis node actually exists

Right now we assume consul is used in 3k and above architectures where a separate Redis node exists. Hence we do the following logic to decide whether to populate Sentinel information to Consul nodes or not

{% if (groups | select('match', '^redis_sentinel.*') | list | count == 0) %}

However, this miss the scenario where Consul is used without a dedicated Redis node at all (i.e, when Redis is bundled in the Rails application node). We should also add a check for that in the if condition.