pluto panics when specifying an https-proxy without a URL scheme

[ginglis13]

Related: bottlerocket-os/bottlerocket-project-website#499

What I expected to happen:

I can set settings.network.https-proxy without a URL scheme as per Bottlerocket documentation https://bottlerocket.dev/en/os/1.26.x/api/settings/network/#https-proxy

What actually happened:

Starting Generate additional settings for Kubernetes...
[    9.515344] pluto[1048]: thread 'main' panicked at aws-smithy-experimental/src/hyper_1_0.rs:259:49:
[FAILED] Failed to start Generate additional settings for Kubernetes.
See 'systemctl status pluto.service' for details.
[    9.570493] pluto[1048]: Unable to parse HTTPS proxy as URL: RelativeUrlWithoutBase
[DEPEND] Dependency failed for Applies settings to create config files.
[    9.690248] pluto[1048]: note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
[DEPEND] Dependency failed for Bootstrap Commands.
[DEPEND] Dependency failed for Bottlerocket initial configuration complete.
[DEPEND] Dependency failed for Isolates configured.target.
[DEPEND] Dependency failed for Sets the hostname.
[DEPEND] Dependency failed for Send signal to CloudFormation Stack.

How to reproduce the problem:

On any Bottlerocket node >= v1.17.0 (bug introduced in bottlerocket-os/bottlerocket@6a66851), launch a node with

  [settings.network]
    https-proxy = "10.0.5.67:8080"

and observe the error.