Support HTTPS when using a specific API instance

[acejam]

The --api flag in Kubo is not currently usable with an API instance behind TLS. This change allows HTTPS to be used.

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[lidel]

Thank you for opening this.

I am afraid hardcoding port is not the right approach – we should simply respect explicitly passed https:// scheme, when passed, and make Kubo pass it, when addr passed to ipfs --api has /https or /tls/http.

Let's continue in #277