bug: passing shard 0 to createEncoder will generate a pubsubtopic with shard 1

[fbarbu15]

This is a bug report

Steps

1. ContentTopic = "/waku/2/content/test.js";
2. singleShardInfo = { clusterId: 0, shard: 0 }
3. encoder = createEncoder({
   contentTopic: ContentTopic,
   pubsubTopicShardInfo: singleShardInfo
   });

Generates:

Encoder {
  contentTopic: '/waku/2/content/test.js',
  ephemeral: false,
  pubsubTopic: '/waku/2/rs/0/1',
  metaSetter: undefined
}

I was expecting /waku/2/rs/0/0 since shard 0 should be valid according to https://rfc.vac.dev/spec/51//#algorithm