[Java] Extra comma in arguments when generating Retrofit2 api

Description

When I tries to generate apis using Retrofit2 I got uncompilable code because of extra commas

// skipped

public interface UserApi {
  
  /**
   * Get information about user
   * An application should invoke this method just after the open session step to know the user's account description.  A server application which is interested by retrieving data of the user using this method must invoke it only when it is necessary and then cache the result. 
   * @param alcUserId Identifier of the Session (required)
   * @param loginName Login name of the user to retrieve the account description. (required)
   * @return Call<User>
   */

  @GET("users/{loginName}")
  Call<User> getUserInfo(
     ,@retrofit2.http.Path("loginName") String loginName
  );

}

Note comma before @retrofit2.http.Path("loginName") String loginName.

Swagger-codegen version

3.0.0-SNAPSHOT

Swagger declaration file content or url

Yaml file is here:
https://gist.github.com/Klemsus/f58803b8c94832705dec4b3895f27d49

Command line used for generation

java -jar swagger-codegen-cli.jar generate -l java -o rest -i userapi.yml -Dlibrary=retrofit2

Steps to reproduce

1. Generate API
2. Open in IDE - it shows an error

Suggest a fix/enhancement

The problem is in cookie type argument that parsed into empty argument (and this is correct behavior, I don't want this as argument), but comma still appears.

Reproduce the issue with the linked YAML and the shown swagger-codegen command using the Retrofit2 library, then inspect how the Java API method arguments are rendered when the cookie type argument is empty. Done means the generated UserApi.java has no leading comma before the loginName parameter and compiles successfully.