fixed enum duplication issue

Author: HugoMario

src/main/resources/handlebars/aspnetcore/model.mustache

@@ -19,7 +19,7 @@ namespace {{packageName}}.Models
     /// </summary>
     [DataContract]
     public partial class {{classname}} : {{#parent}}{{{parent}}}, {{/parent}}IEquatable<{{classname}}>
-    { {{#vars}}{{#isEnum}}{{>enumClass}}{{/isEnum}}{{#items.isEnum}}{{#items}}{{>enumClass}}{{/items}}{{/items.isEnum}}
+    { {{#vars}}{{#isEnum}}{{^complexType}}{{>enumClass}}{{/complexType}}{{/isEnum}}{{#items.isEnum}}{{#items}}{{^complexType}}{{>enumClass}}{{/complexType}}{{/items}}{{/items.isEnum}}
         /// <summary>
         /// {{^description}}Gets or Sets {{{name}}}{{/description}}{{#description}}{{description}}{{/description}}
         /// </summary>