Refactored MtApi4 (MT4) for working with new architecture

MtApi/MtApiTimeConverter.cs

@@ -1,15 +1,10 @@
-using System;
-using System.Collections.Generic;
-using System.Linq;
-using System.Text;
-
-namespace MtApi
+namespace MtApi
 {
     class MtApiTimeConverter
     {
         public static DateTime ConvertFromMtTime(int time)
         {
-            DateTime tmpTime = new DateTime(1970, 1, 1);
+            DateTime tmpTime = new(1970, 1, 1);
             return new DateTime(tmpTime.Ticks + (time * 0x989680L));
         }
 
@@ -18,7 +13,7 @@ namespace MtApi
             int result = 0;
             if (time != null && time != DateTime.MinValue)
             {
-                DateTime tmpTime = new DateTime(1970, 1, 1);
+                DateTime tmpTime = new(1970, 1, 1);
                 result = (int)((time.Value.Ticks - tmpTime.Ticks) / 0x989680L);
             }
             return result;