Index build is failing when specifying secure port

Problem

Index is failed to be built when specifying secure admin port 18091 on the nodes.

Background

Sometimes Sysadmin block port 8091 due to security reasons.

Hence this issue is not allowing this systems to create an index on a specific node.

steps to reproduce

1. make sure port 18091 is accessible 
2. make sure you have query and index service on that node
3. try to create an index while specifying the secure port

create index ix_foo on `travel-sample` (field_xx) 

WITH { "nodes":[ "cb001.localdomain:18091" ]}

1. Index create fails

[

  {

    "code": 5000,

    "msg": "GSI CreateIndex() - cause: Indexer node (cb001.localdomain:18091) not found. The node may be failed or under rebalance or network partitioned from query process.",

    "query": "create index ix_foo on `travel-sample` (field_xx) \nWITH { \"nodes\":[ \"cb001.localdomain:18091\" ] }"

  }

]

5. it works with specifying port 8091.

It is failing with 6.5.0 and 6.0.3, I haven't checked for earlier releases but I guess it is failing as well.