Refactor Server class: move createRooms call outside constructor and update access modifier for _socket

main.cpp

@@ -5,6 +5,7 @@
 int main(int, char **) {
     auto config = std::make_shared<Yc::Lib::Config>();
     auto server = std::make_shared<Yc::Lib::Server>(config);
+    server->createRooms(config->group("rooms"));
     server->run();
     return 0;
 }