Fix for issue: #2307

Remove if queue empty check that does not reset running flag. If the queue was already emptied out already by the previous ExecuteQueue, then this way it will always reset running flag back to 0.

LiteDB/Engine/Disk/DiskWriterQueue.cs

@@ -1,12 +1,7 @@
 using System;
 using System.Collections.Concurrent;
-using System.Collections.Generic;
-using System.ComponentModel;
 using System.IO;
 using System.Linq;
-using System.Reflection;
-using System.Text;
-using System.Text.RegularExpressions;
 using System.Threading;
 using System.Threading.Tasks;
 using static LiteDB.Constants;
@@ -24,7 +19,7 @@ internal class DiskWriterQueue : IDisposable
         // async thread controls
         private Task _task;
 
-        private ConcurrentQueue<PageBuffer> _queue = new ConcurrentQueue<PageBuffer>();
+        private readonly ConcurrentQueue<PageBuffer> _queue = new ConcurrentQueue<PageBuffer>();
 
         private int _running = 0;
 
@@ -92,8 +87,6 @@ public void Wait()
         /// </summary>
         private void ExecuteQueue()
         {
-            if (_queue.Count == 0) return;
-
             do
             {
                 if (_queue.TryDequeue(out var page))