Wrap brackets only for IPv6 address

[SSushmitha8]

Fixes https://github.com/miniohq/aistor-console/issues/5067

When minio runs on port 443, for api calls that uses minio-go in console throws error (api calls that uses madmin-go works fine)

ip.To16() always returns non-nil for valid IPs → wraps ALL IPs in brackets

{
    "errorMessage": "parse \"https://[127.0.0.1]/abc/?location=\": invalid IPv6 host",
    "detailedError": "parse \"https://[127.0.0.1]/abc/?location=\": invalid IPv6 host",
    "validations": []
}

[ramondeklein]

@SSushmitha8 It looks like this line also needs patching: https://github.com/minio/minio-go/blob/master/api.go#L1053

[SSushmitha8]

@SSushmitha8 It looks like this line also needs patching: https://github.com/minio/minio-go/blob/master/api.go#L1053

I thought that's the right condition - if it's not a valid ip4 convert to ip6. Is there a issue that I could test to confirm @ramondeklein