Fix whitespace error in recent patch

patches/server/Fix-player-kick-on-shutdown.patch

@@ -17,7 +17,7 @@ index 0000000000000000000000000000000000000000..00000000000000000000000000000000
      public static <T extends PacketListener> void ensureRunningOnSameThread(Packet<T> packet, T listener, BlockableEventLoop<?> engine) throws RunningOnDifferentThreadException {
          if (!engine.isSameThread()) {
 -            engine.executeIfPossible(() -> {
-+            engine.execute(() -> { // Paper - Fix preemptive player kick on a server shutdown. 
++            engine.execute(() -> { // Paper - Fix preemptive player kick on a server shutdown.
                  packetProcessing.push(listener); // Paper - detailed watchdog information
                  try { // Paper - detailed watchdog information
                  if (MinecraftServer.getServer().hasStopped() || (listener instanceof ServerGamePacketListenerImpl && ((ServerGamePacketListenerImpl) listener).processedDisconnect)) return; // CraftBukkit, MC-142590