Enum on path parameter causing syntax error

Description

Came across an issue where if I have an Enum as a path parameter for a request, the generated api causes Java syntax errors.

It works fine if the parameter is a query parameter.

Swagger-codegen version

2.3.0

Swagger declaration file content or url

---
swagger: '2.0'
info:
  version: 0.0.0
  title: Simple API
paths:
  /users/{userType}:
    get:
      parameters:
        - name: userType
          in: path
          required: true
          type: string
          enum: [admin,normal]
      responses:
        200:
          description: OK

Steps to reproduce

Just generating the api with the above yaml causes a syntax error on the interface method header.
allowableValues="{values=[admin, normal], enumVars=[{name=ADMIN, value="admin"}, {name=NORMAL, value="normal"}]}"

Use the supplied Swagger 2.0 YAML declaration to generate the Java API and inspect the interface method header for the path parameter. Done means the generated Java is syntactically valid when the path parameter has enum values, while the query-parameter case continues to work.