fix: GetMember used to have two copies of GetDefaultMember instead of just a single one

src/util/io/get_member.hpp

@@ -65,7 +65,7 @@ class GetDefaultMember {
 
 /// Find a member with a specific name using reflection
 /** The member is wrapped in a ScriptValue */
-class GetMember : private GetDefaultMember {
+class GetMember {
   public:
 	/// Construct a member getter that looks for the given name
 	GetMember(const String& name);