remove check in map schema

Author: wing328

modules/openapi-generator/src/main/java/org/openapitools/codegen/utils/ModelUtils.java

@@ -439,11 +439,11 @@ public static boolean isComposedSchema(Schema schema) {
      * @return true if the specified schema is a Map schema.
      */
     public static boolean isMapSchema(Schema schema) {
-        // make sure it's not free form object first
-        if (isFreeFormObject(schema)) {
-            // to cover `additionalProperties: {}`
-            return false;
-        }
+//        // make sure it's not free form object first
+//        if (isFreeFormObject(schema)) {
+//            // to cover `additionalProperties: {}`
+//            return false;
+//        }
 
         if (schema instanceof MapSchema) {
             return true;