fix(core): Fixes issues with deserialization due to bad checking of dirty tracking (#618)

Fixes a major issue where serialization was not respecting the dirty tracking feature flag.

Projects/Server/Serialization/ISerializable.cs

@@ -39,6 +39,14 @@ namespace Server
         public void InitializeSaveBuffer(byte[] buffer)
         {
             SaveBuffer = new BufferWriter(buffer, true);
+            if (World.DirtyTrackingEnabled)
+            {
+                SavePosition = SaveBuffer.Position;
+            }
+            else
+            {
+                SavePosition = -1;
+            }
         }
 
         public void Serialize()
@@ -59,6 +67,10 @@ namespace Server
             {
                 SavePosition = SaveBuffer.Position;
             }
+            else
+            {
+                SavePosition = -1;
+            }
         }
     }
 }