Avoid ListenBucket targets to be listed in ServerInfo (#6340)
Avoid ListenBucket targets to be listed in ServerInfo (#6340)

In current master when you do `mc watch` you can see a
dynamic ARN being listed which exposes the remote IP as well

```
mc watch play/airlines
```

On another terminal
```
mc admin info play
●  play.minio.io:9000
   Uptime : online since 11 hours ago
  Version : 2018-08-22T07:50:45Z
   Region :
 SQS ARNs : arn:minio:sqs::httpclient+51c39c3f-131d-42d9-b212-c5eb1450b9ee+73.222.245.195:33408
    Stats : Incoming 30GiB, Outgoing 7.6GiB
  Storage : Used 7.7GiB
```

SQS ARNs listed as part of ServerInfo should be only external targets,
since listing an ARN here is not useful and it cannot be re-purposed in
any manner.

This PR fixes this issue by filtering out httpclient from the ARN list.

This is a regression introduced in #5294 0e4431725cd85236d3d18643f8fc2506c7d88c66
NitishT/minio,harshavardhana/minio,krishnasrinivas/minio,NitishT/minio,minio/minio,aead/minio,minio/minio,krisis/minio,krishnasrinivas/minio,balamurugana/minio,harshavardhana/minio,aead/minio,jimjag/minio,jimjag/minio,fwessels/minio,vadmeste/minio,fwessels/minio,aead/minio,balamurugana/minio,donatello/minio,aead/minio,harshavardhana/minio,donatello/minio,harshavardhana/minio,NitishT/minio,vadmeste/minio,aead/minio,krishnasrinivas/minio,harshavardhana/minio,fwessels/minio,harshavardhana/minio,aead/minio,harshavardhana/minio,aead/minio,jimjag/minio,harshavardhana/minio,krishnasrinivas/minio,jimjag/minio,aead/minio,NitishT/minio,fwessels/minio,krisis/minio