Fix implementation of ContextifyContext::PropertySetterCallback() (#194)

V8 doesn not allow returning arbitrary values from the interceptor
setter callbacks, only a boolean return value is allowed. Since
default return value is "true" it's not even necessary to set
the return value on a successful path.

See https://crbug.com/348660658 for details.

src/node_contextify.cc

@@ -567,7 +567,6 @@ Intercepted ContextifyContext::PropertySetterCallback(
     // property
     if (desc_obj->HasOwnProperty(context, env->get_string()).FromMaybe(false) ||
         desc_obj->HasOwnProperty(context, env->set_string()).FromMaybe(false)) {
-      args.GetReturnValue().Set(value);
       return Intercepted::kYes;
     }
   }