fix(webapi): Fix Swagger URL for new APIM (#755)

<!--- Provide a general summary of your changes in the Title above -->

## Description

<!--- Describe your changes in detail -->

## Related Issue(s)

- #754 

## Verification

- [x] **Your** code builds clean without any errors or warnings
- [x] Manual testing done (required)
- [ ] Relevant automated test added (if you find this hard, leave it and
we'll help out)

## Documentation

- [ ] Documentation is updated (either in `docs`-directory, Altinnpedia
or a separate linked PR in
[altinn-studio-docs.](https://github.com/Altinn/altinn-studio-docs), if
applicable)

Co-authored-by: Ole Jørgen Skogstad <skogstad@softis.net>

src/Digdir.Domain.Dialogporten.WebApi/Program.cs

@@ -188,9 +188,6 @@ static void BuildAndRun(string[] args)
         {
             // Hide schemas view
             uiConfig.DefaultModelsExpandDepth = -1;
-            // We have to add dialogporten here to get the correct base url for swagger.json in the APIM. Should not be done for development
-            var dialogPrefix = builder.Environment.IsDevelopment() ? "" : "/dialogporten";
-            uiConfig.DocumentPath = dialogPrefix + "/swagger/{documentName}/swagger.json";
         });
     app.MapControllers();
     app.MapHealthChecks("/healthz");