[BUG][Golang][Client] Configured Scheme is ignored by generated methods

Created by: johanbrandhorst

Description

The Go client library takes a configurable Scheme, but it then doesn't use it when making client requests.

openapi-generator version

v4.0.0 via https://hub.docker.com/r/openapitools/openapi-generator-cli/

Command line used for generation

docker run --rm -v $(pwd):/local openapitools/openapi-generator-cli:v4.0.0 generate --package-name api -i /local/swagger.json -g go -o /local/api

Steps to reproduce

Attempt to make a request using a Go client generated with v4.0.0.

Related issues/PRs

None

Suggest a fix

This should be reasonably easy to fix, simply adding a case for the Scheme like there is for the host in prepareRequest: https://github.com/OpenAPITools/openapi-generator/blob/18b66ed28c7a2c783e7c4e3c81f1817ec3cabf4f/modules/openapi-generator/src/main/resources/go/client.mustache#L278