Fix some issues with transferring conn back to server

src/connection.cpp

@@ -9,18 +9,19 @@
 
 std::unique_ptr<Connection>
 Connection::createForServer(struct sockaddr_storage addr, int fd, int64_t id,
-                            ConnectionHandler *handler,
+                            size_t epoll_index, ConnectionHandler *handler,
                             std::weak_ptr<Server> server) {
   // Use unique_ptr constructor with private access (friend function)
   // We can't use make_unique here because constructor is private
   return std::unique_ptr<Connection>(
-      new Connection(addr, fd, id, handler, server));
+      new Connection(addr, fd, id, epoll_index, handler, server));
 }
 
 Connection::Connection(struct sockaddr_storage addr, int fd, int64_t id,
-                       ConnectionHandler *handler, std::weak_ptr<Server> server)
-    : fd_(fd), id_(id), addr_(addr), arena_(), handler_(handler),
-      server_(server) {
+                       size_t epoll_index, ConnectionHandler *handler,
+                       std::weak_ptr<Server> server)
+    : fd_(fd), id_(id), epoll_index_(epoll_index), addr_(addr), arena_(),
+      handler_(handler), server_(server) {
   if (auto server_ptr = server_.lock()) {
     server_ptr->active_connections_.fetch_add(1, std::memory_order_relaxed);
   }