[csharp-netcore] Generic Host: Server port is ignored in API requests

Bug Report Checklist

• Have you provided a full/minimal spec to reproduce the issue?
• Have you validated the input using an OpenAPI validator (example)?
• Have you tested with the latest master to confirm the issue still exists?
• Have you searched for related issues/PRs?
• What's the actual output vs expected output?
• [Optional] Sponsorship to speed up the bug fix or feature request (example)

Description

openapi-generator version

6.0.1

OpenAPI declaration file content or url

any file that specifies a server with a non-standard port (ie. not port 80 for http, or port 443 for https)

Generation Details

In the ASP.Net WebApi Project, use swagger with following server addition:

    app.UseSwagger(options =>
        options.PreSerializeFilters.Add((swagger, httpReq) =>
            swagger.Servers = new List<OpenApiServer>
            {
                new OpenApiServer
                {
                    Url = "https://localhost.7080",
                    Description = "My Awesome API"
                }
            }
        ));

Generate client code:

java -jar openapi-generator-cli-6.0.1.jar generate \
  -i myApiDefinition.json \
  -g csharp-netcore \
  -c config.json \
  -o ./client-stub

and here the config.json:

{
	"packageName": "TemplateApi",
	"optionalAssemblyInfo": true,
	"optionalProjectFile": true,
	"targetFramework": "net6.0",
	"modelPropertyNaming": "original",
	"netCoreProjectFile": true,
	"library": "generichost"
}

Steps to reproduce

• Run a REST server on a non-standard Port
• generate openApi.json containing the server path
• try using the client

Expected Results

I'd expect the client to correctly use the host AND port of the given server

Actual Results

The client fails to connect to the server, as it tries connecting to the standard port of the given scheme

Related issues/PRs

#12795

Reproduce with the provided openapi.json server definition using https://localhost:7080, the csharp-netcore generator, and config.json. Inspect the generated client’s request setup and confirm that requests use the declared host and non-standard port instead of the scheme’s default port.