[Question] hasJsonConstructor in vertx/codegen/DataObjectModel.java

Hello,

More of a question,

I'm trying to customize the vertx-proxygen templates to not use a constructor that requires a JsonObject but I get stopped by this bit here.

With this bit removed and by using custom templates for proxy gen that uses static factory method I don't seem to have any issues.

vertx/codegen/DataObjectModel.java
```java

boolean hasJsonConstructor = (constructors & 2) == 2;

if (concrete && !hasJsonConstructor) {
throw new GenException(modelElt, "Data object " + modelElt + " class does not have a constructor " + modelElt.getSimpleName() + "(" + JsonObject.class.getSimpleName() + ")");
}
```

Alternatively does anyone have a working example of using kotlin data class with proxy-gen? The only way I could get it to work was to hack out this bit above and change the template to use jackson deserialization instead of `new T(JsonObject).`

on v3.7.0