ProxyFixMiddleware: Turns out GCP LBs and possibly AWS LBs only have one value in x-forwarded-proto

[nabheet]

I am not sure about the best way to handle this test case if there are multiple IPs in X-Forwarded-For but only one value in X-Forwarded-Proto (or not the same amount).

In GCP, X-Forward-Proto always has only one value.

In AWS, X-Forwarded-Proto always has only one value.

[nabheet]

Looks like MDN also assumes single value.

Wondering if the best way to handle it is to use the hops if that many values exist, otherwise default to the first one from the left. Or if we have hops set to 5, but only 4 x-forwarded-proto headers exist, maybe use the first one from the left as that would be the last one from the right. Man this is so confusing!!! 😄