Reload spam freezes game logic

Spamming the reload command may stop the game logic from working.

You can still fly around and break blocks, but nothing moves and reacts to anything.

Saving the game at this point in time is not possible, the only solution is to kill the process.

Steps to reproduce:

1. Create a new world.

2. Try to break some blocks and execute some commands; that should work.

3. Execute /reload and wait a bit.

4. Repeat step (2); it should still work.

5. Spam /reload by pressing the following keys quickly after each other in this sequence: T, Up, Enter.

6. Wait a little bit.

7. Try step (2); it may still work. If it still works, go to step (5).

8. Game logic is frozen.