fix: fix bot spawn problem

lophine-server/src/main/java/org/leavesmc/leaves/bot/ServerBotPacketListenerImpl.java

@@ -75,6 +75,10 @@ public class ServerBotPacketListenerImpl extends ServerGamePacketListenerImpl {
         public void tick() {
         }
 
+        @Override
+        public void flushChannel() {
+        }
+
         @Override
         public boolean isConnected() {
             return true;