Fix list value cannot be de-serialized

[Karlatemp]

After 621e791, deserialize hocon config list value will got wrong thing.

As example, deserializing following config

subnode = [
  114, 514
]

will got wrong response:

var node = HoconConfiguationLoader.builder().file(....).load();
var subnode = node.node("subnode");

System.out.println(subnode.isMap()); // true
System.out.println(subnode.raw()); // {1=514}

[jpenilla]

Tested to fix #411