lightning-liquidity LSPS5 URL doesn't validate https-only when deserializing

[TheBlueMatt]

We should fix this.

Commit should include a reported-by Thomas Kilbride of Block Security

[vincenzopalazzo]

I was stuck in a meeting that was not productive, and I got distracted by fixing this issue, but not sure if the PR #4560 is complete, fur for sure should be a good starting point