[C#] v2.4.1 Void Instead of ModelVoid

Description

I'm seeing broken C#.NET ("csharp" gen option) generated code from online CodeGen (2.4.1 SNAPSHOT) for the same definitions which were fine with 2.3.1.

Swagger-codegen version

Currently, 2.4.1 SNAPSHOT but I use the online generator so have no control over this.

Error

'Void' is an ambiguous reference between '{ApiName}.Model.Void' and 'void'

Command line used for generation

Steps to reproduce

There're no steps to reproduce the difference as only the latest CodeGen version is available.

Suggest a fix/enhancement

I don't understand why a SNAPSHOT release is being used by the online CodeGen rather than the latest stable release. I'd suggest using the latest stable release instead.
Also, it would be excellent if there were a URL option to specify the CodeGen version, eg http://generator.swagger.io/api/gen231/clients/csharp ... where 231 represents version 2.3.1.

Start with the online CodeGen C# generation path and compare output from 2.3.1 with the reported 2.4.1 SNAPSHOT behavior. Confirm where the generated Model.Void reference becomes ambiguous with void, then verify whether the online generator's version selection can be changed or pinned to a stable release.