Update camel http.scheme/http.url if spec is updated

[trask]

Tracking issue so we don't forget to update the camel instrumentation if/when spec is clarified open-telemetry/opentelemetry-specification#2171.

The question is whether to capture the url as it was passed in by the user (e.g. http4://) instead of current behavior which models the actual downstream request (e.g. http://).

See discussion at #4650 (comment)

[trask]

Closing, can revisit later if anyone has renewed interest.